editors/sed.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sed.c - very minimalist version of sed
   4  *
   5  * Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley
   6  * Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org>
   7  * Copyright (C) 2002  Matt Kraai
   8  * Copyright (C) 2003 by Glenn McGrath <bug1@iinet.net.au>
   9  * Copyright (C) 2003,2004 by Rob Landley <rob@landley.net>
  10  *
  11  * MAINTAINER: Rob Landley <rob@landley.net>
  12  *
  13  * Licensed under GPL version 2, see file LICENSE in this tarball for details.
  14  */
  15
  16 /* Code overview.
  17
  18   Files are laid out to avoid unnecessary function declarations.  So for
  19   example, every function add_cmd calls occurs before add_cmd in this file.
  20
  21   add_cmd() is called on each line of sed command text (from a file or from
  22   the command line).  It calls get_address() and parse_cmd_args().  The
  23   resulting sed_cmd_t structures are appended to a linked list
  24   (bbg.sed_cmd_head/bbg.sed_cmd_tail).
  25
  26   add_input_file() adds a FILE * to the list of input files.  We need to
  27   know all input sources ahead of time to find the last line for the $ match.
  28
  29   process_files() does actual sedding, reading data lines from each input FILE *
  30   (which could be stdin) and applying the sed command list (sed_cmd_head) to
  31   each of the resulting lines.
  32
  33   sed_main() is where external code calls into this, with a command line.
  34 */
  35
  36
  37 /*
  38         Supported features and commands in this version of sed:
  39
  40          - comments ('#')
  41          - address matching: num|/matchstr/[,num|/matchstr/|$]command
  42          - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags)
  43          - edit commands: (a)ppend, (i)nsert, (c)hange
  44          - file commands: (r)ead
  45          - backreferences in substitution expressions (\0, \1, \2...\9)
  46          - grouped commands: {cmd1;cmd2}
  47          - transliteration (y/source-chars/dest-chars/)
  48          - pattern space hold space storing / swapping (g, h, x)
  49          - labels / branching (: label, b, t, T)
  50
  51          (Note: Specifying an address (range) to match is *optional*; commands
  52          default to the whole pattern space if no specific address match was
  53          requested.)
  54
  55         Todo:
  56          - Create a wrapper around regex to make libc's regex conform with sed
  57
  58         Reference http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html
  59 */
  60
  61 #include "busybox.h"
  62 #include "xregex.h"
  63
  64 /* Each sed command turns into one of these structures. */
  65 typedef struct sed_cmd_s {
  66         /* Ordered by alignment requirements: currently 36 bytes on x86 */
  67
  68         /* address storage */
  69         regex_t *beg_match;     /* sed -e '/match/cmd' */
  70         regex_t *end_match;     /* sed -e '/match/,/end_match/cmd' */
  71         regex_t *sub_match;     /* For 's/sub_match/string/' */
  72         int beg_line;           /* 'sed 1p'   0 == apply commands to all lines */
  73         int end_line;           /* 'sed 1,3p' 0 == one line only. -1 = last line ($) */
  74
  75         FILE *file;             /* File (sw) command writes to, -1 for none. */
  76         char *string;           /* Data string for (saicytb) commands. */
  77
  78         unsigned short which_match;     /* (s) Which match to replace (0 for all) */
  79
  80         /* Bitfields (gcc won't group them if we don't) */
  81         unsigned int invert:1;          /* the '!' after the address */
  82         unsigned int in_match:1;        /* Next line also included in match? */
  83         unsigned int no_newline:1;      /* Last line written by (sw) had no '\n' */
  84         unsigned int sub_p:1;           /* (s) print option */
  85
  86         /* GENERAL FIELDS */
  87         char cmd;               /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
  88         struct sed_cmd_s *next; /* Next command (linked list, NULL terminated) */
  89 } sed_cmd_t;
  90
  91 static const char *const semicolon_whitespace = "; \n\r\t\v";
  92
  93 struct sed_globals
  94 {
  95         /* options */
  96         int be_quiet, in_place, regex_type;
  97         FILE *nonstdout;
  98         char *outname, *hold_space;
  99
 100         /* List of input files */
 101         int input_file_count,current_input_file;
 102         FILE **input_file_list;
 103
 104         regmatch_t regmatch[10];
 105         regex_t *previous_regex_ptr;
 106
 107         /* linked list of sed commands */
 108         sed_cmd_t sed_cmd_head, *sed_cmd_tail;
 109
 110         /* Linked list of append lines */
 111         llist_t *append_head;
 112
 113         char *add_cmd_line;
 114
 115         struct pipeline {
 116                 char *buf;      /* Space to hold string */
 117                 int idx;        /* Space used */
 118                 int len;        /* Space allocated */
 119         } pipeline;
 120 } bbg;
 121
 122
 123 void sed_free_and_close_stuff(void);
 124 #if ENABLE_FEATURE_CLEAN_UP
 125 void sed_free_and_close_stuff(void)
 126 {
 127         sed_cmd_t *sed_cmd = bbg.sed_cmd_head.next;
 128
 129         llist_free(bbg.append_head, free);
 130
 131         while (sed_cmd) {
 132                 sed_cmd_t *sed_cmd_next = sed_cmd->next;
 133
 134                 if (sed_cmd->file)
 135                         xprint_and_close_file(sed_cmd->file);
 136
 137                 if (sed_cmd->beg_match) {
 138                         regfree(sed_cmd->beg_match);
 139                         free(sed_cmd->beg_match);
 140                 }
 141                 if (sed_cmd->end_match) {
 142                         regfree(sed_cmd->end_match);
 143                         free(sed_cmd->end_match);
 144                 }
 145                 if (sed_cmd->sub_match) {
 146                         regfree(sed_cmd->sub_match);
 147                         free(sed_cmd->sub_match);
 148                 }
 149                 free(sed_cmd->string);
 150                 free(sed_cmd);
 151                 sed_cmd = sed_cmd_next;
 152         }
 153
 154         if (bbg.hold_space) free(bbg.hold_space);
 155
 156         while (bbg.current_input_file < bbg.input_file_count)
 157                 fclose(bbg.input_file_list[bbg.current_input_file++]);
 158 }
 159 #endif
 160
 161 /* If something bad happens during -i operation, delete temp file */
 162
 163 static void cleanup_outname(void)
 164 {
 165         if (bbg.outname) unlink(bbg.outname);
 166 }
 167
 168 /* strdup, replacing "\n" with '\n', and "\delimiter" with 'delimiter' */
 169
 170 static void parse_escapes(char *dest, char *string, int len, char from, char to)
 171 {
 172         int i = 0;
 173
 174         while (i < len) {
 175                 if (string[i] == '\\') {
 176                         if (!to || string[i+1] == from) {
 177                                 *(dest++) = to ? to : string[i+1];
 178                                 i += 2;
 179                                 continue;
 180                         } else *(dest++) = string[i++];
 181                 }
 182                 *(dest++) = string[i++];
 183         }
 184         *dest = 0;
 185 }
 186
 187 static char *copy_parsing_escapes(char *string, int len)
 188 {
 189         char *dest = xmalloc(len+1);
 190
 191         parse_escapes(dest,string,len,'n','\n');
 192         return dest;
 193 }
 194
 195
 196 /*
 197  * index_of_next_unescaped_regexp_delim - walks left to right through a string
 198  * beginning at a specified index and returns the index of the next regular
 199  * expression delimiter (typically a forward * slash ('/')) not preceded by
 200  * a backslash ('\').  A negative delimiter disables square bracket checking.
 201  */
 202 static int index_of_next_unescaped_regexp_delim(int delimiter, char *str)
 203 {
 204         int bracket = -1;
 205         int escaped = 0;
 206         int idx = 0;
 207         char ch;
 208
 209         if (delimiter < 0) {
 210                 bracket--;
 211                 delimiter *= -1;
 212         }
 213
 214         for (; (ch = str[idx]); idx++) {
 215                 if (bracket >= 0) {
 216                         if (ch == ']' && !(bracket == idx - 1 || (bracket == idx - 2
 217                                         && str[idx - 1] == '^')))
 218                                 bracket = -1;
 219                 } else if (escaped)
 220                         escaped = 0;
 221                 else if (ch == '\\')
 222                         escaped = 1;
 223                 else if (bracket == -1 && ch == '[')
 224                         bracket = idx;
 225                 else if (ch == delimiter)
 226                         return idx;
 227         }
 228
 229         /* if we make it to here, we've hit the end of the string */
 230         bb_error_msg_and_die("unmatched '%c'",delimiter);
 231 }
 232
 233 /*
 234  *  Returns the index of the third delimiter
 235  */
 236 static int parse_regex_delim(char *cmdstr, char **match, char **replace)
 237 {
 238         char *cmdstr_ptr = cmdstr;
 239         char delimiter;
 240         int idx = 0;
 241
 242         /* verify that the 's' or 'y' is followed by something.  That something
 243          * (typically a 'slash') is now our regexp delimiter... */
 244         if (*cmdstr == '\0')
 245                 bb_error_msg_and_die("bad format in substitution expression");
 246         delimiter = *cmdstr_ptr++;
 247
 248         /* save the match string */
 249         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 250         *match = copy_parsing_escapes(cmdstr_ptr, idx);
 251
 252         /* save the replacement string */
 253         cmdstr_ptr += idx + 1;
 254         idx = index_of_next_unescaped_regexp_delim(-delimiter, cmdstr_ptr);
 255         *replace = copy_parsing_escapes(cmdstr_ptr, idx);
 256
 257         return ((cmdstr_ptr - cmdstr) + idx);
 258 }
 259
 260 /*
 261  * returns the index in the string just past where the address ends.
 262  */
 263 static int get_address(char *my_str, int *linenum, regex_t ** regex)
 264 {
 265         char *pos = my_str;
 266
 267         if (isdigit(*my_str)) {
 268                 *linenum = strtol(my_str, &pos, 10);
 269                 /* endstr shouldnt ever equal NULL */
 270         } else if (*my_str == '$') {
 271                 *linenum = -1;
 272                 pos++;
 273         } else if (*my_str == '/' || *my_str == '\\') {
 274                 int next;
 275                 char delimiter;
 276                 char *temp;
 277
 278                 delimiter = '/';
 279                 if (*my_str == '\\') delimiter = *++pos;
 280                 next = index_of_next_unescaped_regexp_delim(delimiter, ++pos);
 281                 temp = copy_parsing_escapes(pos,next);
 282                 *regex = xmalloc(sizeof(regex_t));
 283                 xregcomp(*regex, temp, bbg.regex_type|REG_NEWLINE);
 284                 free(temp);
 285                 /* Move position to next character after last delimiter */
 286                 pos += (next+1);
 287         }
 288         return pos - my_str;
 289 }
 290
 291 /* Grab a filename.  Whitespace at start is skipped, then goes to EOL. */
 292 static int parse_file_cmd(sed_cmd_t *sed_cmd, char *filecmdstr, char **retval)
 293 {
 294         int start = 0, idx, hack = 0;
 295
 296         /* Skip whitespace, then grab filename to end of line */
 297         while (isspace(filecmdstr[start])) start++;
 298         idx = start;
 299         while (filecmdstr[idx] && filecmdstr[idx] != '\n') idx++;
 300
 301         /* If lines glued together, put backslash back. */
 302         if (filecmdstr[idx] == '\n') hack = 1;
 303         if (idx == start)
 304                 bb_error_msg_and_die("empty filename");
 305         *retval = xstrndup(filecmdstr+start, idx-start+hack+1);
 306         if (hack) (*retval)[idx] = '\\';
 307
 308         return idx;
 309 }
 310
 311 static int parse_subst_cmd(sed_cmd_t *sed_cmd, char *substr)
 312 {
 313         int cflags = bbg.regex_type;
 314         char *match;
 315         int idx = 0;
 316
 317         /*
 318          * A substitution command should look something like this:
 319          *    s/match/replace/ #gIpw
 320          *    ||     |        |||
 321          *    mandatory       optional
 322          */
 323         idx = parse_regex_delim(substr, &match, &sed_cmd->string);
 324
 325         /* determine the number of back references in the match string */
 326         /* Note: we compute this here rather than in the do_subst_command()
 327          * function to save processor time, at the expense of a little more memory
 328          * (4 bits) per sed_cmd */
 329
 330         /* process the flags */
 331
 332         sed_cmd->which_match = 1;
 333         while (substr[++idx]) {
 334                 /* Parse match number */
 335                 if (isdigit(substr[idx])) {
 336                         if (match[0] != '^') {
 337                                 /* Match 0 treated as all, multiple matches we take the last one. */
 338                                 char *pos = substr+idx;
 339                                 sed_cmd->which_match = (unsigned short)strtol(substr+idx,&pos,10);
 340                                 idx = pos-substr;
 341                         }
 342                         continue;
 343                 }
 344                 /* Skip spaces */
 345                 if (isspace(substr[idx])) continue;
 346
 347                 switch (substr[idx]) {
 348                 /* Replace all occurrences */
 349                 case 'g':
 350                         if (match[0] != '^') sed_cmd->which_match = 0;
 351                         break;
 352                 /* Print pattern space */
 353                 case 'p':
 354                         sed_cmd->sub_p = 1;
 355                         break;
 356                 /* Write to file */
 357                 case 'w':
 358                 {
 359                         char *temp;
 360                         idx += parse_file_cmd(sed_cmd,substr+idx,&temp);
 361
 362                         break;
 363                 }
 364                 /* Ignore case (gnu exension) */
 365                 case 'I':
 366                         cflags |= REG_ICASE;
 367                         break;
 368                 /* Comment */
 369                 case '#':
 370                         while (substr[++idx]) /*skip all*/;
 371                         /* Fall through */
 372                 /* End of command */
 373                 case ';':
 374                 case '}':
 375                         goto out;
 376                 default:
 377                         bb_error_msg_and_die("bad option in substitution expression");
 378                 }
 379         }
 380 out:
 381         /* compile the match string into a regex */
 382         if (*match != '\0') {
 383                 /* If match is empty, we use last regex used at runtime */
 384                 sed_cmd->sub_match = (regex_t *) xmalloc(sizeof(regex_t));
 385                 xregcomp(sed_cmd->sub_match, match, cflags);
 386         }
 387         free(match);
 388
 389         return idx;
 390 }
 391
 392 /*
 393  *  Process the commands arguments
 394  */
 395 static char *parse_cmd_args(sed_cmd_t *sed_cmd, char *cmdstr)
 396 {
 397         /* handle (s)ubstitution command */
 398         if (sed_cmd->cmd == 's')
 399                 cmdstr += parse_subst_cmd(sed_cmd, cmdstr);
 400         /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
 401         else if (strchr("aic", sed_cmd->cmd)) {
 402                 if ((sed_cmd->end_line || sed_cmd->end_match) && sed_cmd->cmd != 'c')
 403                         bb_error_msg_and_die
 404                                 ("only a beginning address can be specified for edit commands");
 405                 for (;;) {
 406                         if (*cmdstr == '\n' || *cmdstr == '\\') {
 407                                 cmdstr++;
 408                                 break;
 409                         } else if (isspace(*cmdstr))
 410                                 cmdstr++;
 411                         else
 412                                 break;
 413                 }
 414                 sed_cmd->string = xstrdup(cmdstr);
 415                 parse_escapes(sed_cmd->string,sed_cmd->string,strlen(cmdstr),0,0);
 416                 cmdstr += strlen(cmdstr);
 417         /* handle file cmds: (r)ead */
 418         } else if (strchr("rw", sed_cmd->cmd)) {
 419                 if (sed_cmd->end_line || sed_cmd->end_match)
 420                         bb_error_msg_and_die("command only uses one address");
 421                 cmdstr += parse_file_cmd(sed_cmd, cmdstr, &sed_cmd->string);
 422                 if (sed_cmd->cmd == 'w')
 423                         sed_cmd->file = xfopen(sed_cmd->string,"w");
 424         /* handle branch commands */
 425         } else if (strchr(":btT", sed_cmd->cmd)) {
 426                 int length;
 427
 428                 cmdstr = skip_whitespace(cmdstr);
 429                 length = strcspn(cmdstr, semicolon_whitespace);
 430                 if (length) {
 431                         sed_cmd->string = xstrndup(cmdstr, length);
 432                         cmdstr += length;
 433                 }
 434         }
 435         /* translation command */
 436         else if (sed_cmd->cmd == 'y') {
 437                 char *match, *replace;
 438                 int i = cmdstr[0];
 439
 440                 cmdstr += parse_regex_delim(cmdstr, &match, &replace)+1;
 441                 /* \n already parsed, but \delimiter needs unescaping. */
 442                 parse_escapes(match,match,strlen(match),i,i);
 443                 parse_escapes(replace,replace,strlen(replace),i,i);
 444
 445                 sed_cmd->string = xzalloc((strlen(match) + 1) * 2);
 446                 for (i = 0; match[i] && replace[i]; i++) {
 447                         sed_cmd->string[i*2] = match[i];
 448                         sed_cmd->string[i*2+1] = replace[i];
 449                 }
 450                 free(match);
 451                 free(replace);
 452         }
 453         /* if it wasnt a single-letter command that takes no arguments
 454          * then it must be an invalid command.
 455          */
 456         else if (strchr("dDgGhHlnNpPqx={}", sed_cmd->cmd) == 0) {
 457                 bb_error_msg_and_die("unsupported command %c", sed_cmd->cmd);
 458         }
 459
 460         /* give back whatever's left over */
 461         return cmdstr;
 462 }
 463
 464
 465 /* Parse address+command sets, skipping comment lines. */
 466
 467 static void add_cmd(char *cmdstr)
 468 {
 469         sed_cmd_t *sed_cmd;
 470         int temp;
 471
 472         /* Append this line to any unfinished line from last time. */
 473         if (bbg.add_cmd_line) {
 474                 cmdstr = xasprintf("%s\n%s", bbg.add_cmd_line, cmdstr);
 475                 free(bbg.add_cmd_line);
 476                 bbg.add_cmd_line = cmdstr;
 477         }
 478
 479         /* If this line ends with backslash, request next line. */
 480         temp = strlen(cmdstr);
 481         if (temp && cmdstr[temp-1] == '\\') {
 482                 if (!bbg.add_cmd_line)
 483                         bbg.add_cmd_line = xstrdup(cmdstr);
 484                 bbg.add_cmd_line[temp-1] = 0;
 485                 return;
 486         }
 487
 488         /* Loop parsing all commands in this line. */
 489         while (*cmdstr) {
 490                 /* Skip leading whitespace and semicolons */
 491                 cmdstr += strspn(cmdstr, semicolon_whitespace);
 492
 493                 /* If no more commands, exit. */
 494                 if (!*cmdstr) break;
 495
 496                 /* if this is a comment, jump past it and keep going */
 497                 if (*cmdstr == '#') {
 498                         /* "#n" is the same as using -n on the command line */
 499                         if (cmdstr[1] == 'n')
 500                                 bbg.be_quiet++;
 501                         cmdstr = strpbrk(cmdstr, "\n\r");
 502                         if (!cmdstr) break;
 503                         continue;
 504                 }
 505
 506                 /* parse the command
 507                  * format is: [addr][,addr][!]cmd
 508                  *            |----||-----||-|
 509                  *            part1 part2  part3
 510                  */
 511
 512                 sed_cmd = xzalloc(sizeof(sed_cmd_t));
 513
 514                 /* first part (if present) is an address: either a '$', a number or a /regex/ */
 515                 cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
 516
 517                 /* second part (if present) will begin with a comma */
 518                 if (*cmdstr == ',') {
 519                         int idx;
 520
 521                         cmdstr++;
 522                         idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
 523                         if (!idx)
 524                                 bb_error_msg_and_die("no address after comma");
 525                         cmdstr += idx;
 526                 }
 527
 528                 /* skip whitespace before the command */
 529                 cmdstr = skip_whitespace(cmdstr);
 530
 531                 /* Check for inversion flag */
 532                 if (*cmdstr == '!') {
 533                         sed_cmd->invert = 1;
 534                         cmdstr++;
 535
 536                         /* skip whitespace before the command */
 537                         cmdstr = skip_whitespace(cmdstr);
 538                 }
 539
 540                 /* last part (mandatory) will be a command */
 541                 if (!*cmdstr)
 542                         bb_error_msg_and_die("missing command");
 543                 sed_cmd->cmd = *(cmdstr++);
 544                 cmdstr = parse_cmd_args(sed_cmd, cmdstr);
 545
 546                 /* Add the command to the command array */
 547                 bbg.sed_cmd_tail->next = sed_cmd;
 548                 bbg.sed_cmd_tail = bbg.sed_cmd_tail->next;
 549         }
 550
 551         /* If we glued multiple lines together, free the memory. */
 552         free(bbg.add_cmd_line);
 553         bbg.add_cmd_line = NULL;
 554 }
 555
 556 /* Append to a string, reallocating memory as necessary. */
 557
 558 #define PIPE_GROW 64
 559
 560 static void pipe_putc(char c)
 561 {
 562         if (bbg.pipeline.idx == bbg.pipeline.len) {
 563                 bbg.pipeline.buf = xrealloc(bbg.pipeline.buf,
 564                                 bbg.pipeline.len + PIPE_GROW);
 565                 bbg.pipeline.len += PIPE_GROW;
 566         }
 567         bbg.pipeline.buf[bbg.pipeline.idx++] = c;
 568 }
 569
 570 static void do_subst_w_backrefs(char *line, char *replace)
 571 {
 572         int i,j;
 573
 574         /* go through the replacement string */
 575         for (i = 0; replace[i]; i++) {
 576                 /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */
 577                 if (replace[i] == '\\' && replace[i+1] >= '0' && replace[i+1] <= '9') {
 578                         int backref = replace[++i]-'0';
 579
 580                         /* print out the text held in bbg.regmatch[backref] */
 581                         if (bbg.regmatch[backref].rm_so != -1) {
 582                                 j = bbg.regmatch[backref].rm_so;
 583                                 while (j < bbg.regmatch[backref].rm_eo)
 584                                         pipe_putc(line[j++]);
 585                         }
 586                 }
 587
 588                 /* if we find a backslash escaped character, print the character */
 589                 else if (replace[i] == '\\') pipe_putc(replace[++i]);
 590
 591                 /* if we find an unescaped '&' print out the whole matched text. */
 592                 else if (replace[i] == '&') {
 593                         j = bbg.regmatch[0].rm_so;
 594                         while (j < bbg.regmatch[0].rm_eo)
 595                                 pipe_putc(line[j++]);
 596                 }
 597                 /* Otherwise just output the character. */
 598                 else pipe_putc(replace[i]);
 599         }
 600 }
 601
 602 static int do_subst_command(sed_cmd_t *sed_cmd, char **line)
 603 {
 604         char *oldline = *line;
 605         int altered = 0;
 606         int match_count = 0;
 607         regex_t *current_regex;
 608
 609         /* Handle empty regex. */
 610         if (sed_cmd->sub_match == NULL) {
 611                 current_regex = bbg.previous_regex_ptr;
 612                 if (!current_regex)
 613                         bb_error_msg_and_die("no previous regexp");
 614         } else
 615                 bbg.previous_regex_ptr = current_regex = sed_cmd->sub_match;
 616
 617         /* Find the first match */
 618         if (REG_NOMATCH == regexec(current_regex, oldline, 10, bbg.regmatch, 0))
 619                 return 0;
 620
 621         /* Initialize temporary output buffer. */
 622         bbg.pipeline.buf = xmalloc(PIPE_GROW);
 623         bbg.pipeline.len = PIPE_GROW;
 624         bbg.pipeline.idx = 0;
 625
 626         /* Now loop through, substituting for matches */
 627         do {
 628                 int i;
 629
 630                 /* Work around bug in glibc regexec, demonstrated by:
 631                    echo " a.b" | busybox sed 's [^ .]* x g'
 632                    The match_count check is so not to break
 633                    echo "hi" | busybox sed 's/^/!/g' */
 634                 if (!bbg.regmatch[0].rm_so && !bbg.regmatch[0].rm_eo && match_count) {
 635                         pipe_putc(*oldline++);
 636                         continue;
 637                 }
 638
 639                 match_count++;
 640
 641                 /* If we aren't interested in this match, output old line to
 642                    end of match and continue */
 643                 if (sed_cmd->which_match && sed_cmd->which_match!=match_count) {
 644                         for (i = 0; i < bbg.regmatch[0].rm_eo; i++)
 645                                 pipe_putc(*oldline++);
 646                         continue;
 647                 }
 648
 649                 /* print everything before the match */
 650                 for (i = 0; i < bbg.regmatch[0].rm_so; i++)
 651                         pipe_putc(oldline[i]);
 652
 653                 /* then print the substitution string */
 654                 do_subst_w_backrefs(oldline, sed_cmd->string);
 655
 656                 /* advance past the match */
 657                 oldline += bbg.regmatch[0].rm_eo;
 658                 /* flag that something has changed */
 659                 altered++;
 660
 661                 /* if we're not doing this globally, get out now */
 662                 if (sed_cmd->which_match) break;
 663         } while (*oldline && (regexec(current_regex, oldline, 10, bbg.regmatch, 0) != REG_NOMATCH));
 664
 665         /* Copy rest of string into output pipeline */
 666
 667         while (*oldline)
 668                 pipe_putc(*oldline++);
 669         pipe_putc(0);
 670
 671         free(*line);
 672         *line = bbg.pipeline.buf;
 673         return altered;
 674 }
 675
 676 /* Set command pointer to point to this label.  (Does not handle null label.) */
 677 static sed_cmd_t *branch_to(char *label)
 678 {
 679         sed_cmd_t *sed_cmd;
 680
 681         for (sed_cmd = bbg.sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) {
 682                 if (sed_cmd->cmd == ':' && sed_cmd->string && !strcmp(sed_cmd->string, label)) {
 683                         return sed_cmd;
 684                 }
 685         }
 686         bb_error_msg_and_die("can't find label for jump to '%s'", label);
 687 }
 688
 689 static void append(char *s)
 690 {
 691         llist_add_to_end(&bbg.append_head, xstrdup(s));
 692 }
 693
 694 static void flush_append(void)
 695 {
 696         char *data;
 697
 698         /* Output appended lines. */
 699         while ((data = (char *)llist_pop(&bbg.append_head))) {
 700                 fprintf(bbg.nonstdout,"%s\n",data);
 701                 free(data);
 702         }
 703 }
 704
 705 static void add_input_file(FILE *file)
 706 {
 707         bbg.input_file_list = xrealloc(bbg.input_file_list,
 708                         (bbg.input_file_count + 1) * sizeof(FILE *));
 709         bbg.input_file_list[bbg.input_file_count++] = file;
 710 }
 711
 712 /* Get next line of input from bbg.input_file_list, flushing append buffer and
 713  * noting if we ran out of files without a newline on the last line we read.
 714  */
 715 static char *get_next_line(int *no_newline)
 716 {
 717         char *temp = NULL;
 718         int len;
 719
 720         flush_append();
 721         while (bbg.current_input_file < bbg.input_file_count) {
 722                 temp = bb_get_chunk_from_file(bbg.input_file_list[bbg.current_input_file],&len);
 723                 if (temp) {
 724                         *no_newline = !(len && temp[len-1] == '\n');
 725                         if (!*no_newline) temp[len-1] = 0;
 726                         break;
 727                 // Close this file and advance to next one
 728                 } else
 729                         fclose(bbg.input_file_list[bbg.current_input_file++]);
 730         }
 731
 732         return temp;
 733 }
 734
 735 /* Output line of text.  missing_newline means the last line output did not
 736    end with a newline.  no_newline means this line does not end with a
 737    newline. */
 738
 739 static int puts_maybe_newline(char *s, FILE *file, int missing_newline, int no_newline)
 740 {
 741         if (missing_newline) fputc('\n',file);
 742         fputs(s,file);
 743         if (!no_newline) fputc('\n',file);
 744
 745         if (ferror(file)) {
 746                 xfunc_error_retval = 4;  /* It's what gnu sed exits with... */
 747                 bb_error_msg_and_die(bb_msg_write_error);
 748         }
 749
 750         return no_newline;
 751 }
 752
 753 #define sed_puts(s,n) missing_newline=puts_maybe_newline(s,bbg.nonstdout,missing_newline,n)
 754
 755 /* Process all the lines in all the files */
 756
 757 static void process_files(void)
 758 {
 759         char *pattern_space, *next_line;
 760         int linenum = 0, missing_newline = 0;
 761         int no_newline,next_no_newline = 0;
 762
 763         /* Prime the pump */
 764         next_line = get_next_line(&next_no_newline);
 765
 766         /* go through every line in each file */
 767         for (;;) {
 768                 sed_cmd_t *sed_cmd;
 769                 int substituted = 0;
 770
 771                 /* Advance to next line.  Stop if out of lines. */
 772                 pattern_space = next_line;
 773                 if (!pattern_space) break;
 774                 no_newline = next_no_newline;
 775
 776                 /* Read one line in advance so we can act on the last line,
 777                  * the '$' address */
 778                 next_line = get_next_line(&next_no_newline);
 779                 linenum++;
 780 restart:
 781                 /* for every line, go through all the commands */
 782                 for (sed_cmd = bbg.sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) {
 783                         int old_matched, matched;
 784
 785                         old_matched = sed_cmd->in_match;
 786
 787                         /* Determine if this command matches this line: */
 788
 789                         /* Are we continuing a previous multi-line match? */
 790                         sed_cmd->in_match = sed_cmd->in_match
 791                                 /* Or is no range necessary? */
 792                                 || (!sed_cmd->beg_line && !sed_cmd->end_line
 793                                         && !sed_cmd->beg_match && !sed_cmd->end_match)
 794                                 /* Or did we match the start of a numerical range? */
 795                                 || (sed_cmd->beg_line > 0 && (sed_cmd->beg_line == linenum))
 796                                 /* Or does this line match our begin address regex? */
 797                                 || (sed_cmd->beg_match &&
 798                                     !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0))
 799                                 /* Or did we match last line of input? */
 800                                 || (sed_cmd->beg_line == -1 && next_line == NULL);
 801
 802                         /* Snapshot the value */
 803
 804                         matched = sed_cmd->in_match;
 805
 806                         /* Is this line the end of the current match? */
 807
 808                         if (matched) {
 809                                 sed_cmd->in_match = !(
 810                                         /* has the ending line come, or is this a single address command? */
 811                                         (sed_cmd->end_line ?
 812                                                 sed_cmd->end_line==-1 ?
 813                                                         !next_line
 814                                                         : sed_cmd->end_line<=linenum
 815                                                 : !sed_cmd->end_match)
 816                                         /* or does this line matches our last address regex */
 817                                         || (sed_cmd->end_match && old_matched && (regexec(sed_cmd->end_match, pattern_space, 0, NULL, 0) == 0))
 818                                 );
 819                         }
 820
 821                         /* Skip blocks of commands we didn't match. */
 822                         if (sed_cmd->cmd == '{') {
 823                                 if (sed_cmd->invert ? matched : !matched)
 824                                         while (sed_cmd && sed_cmd->cmd != '}')
 825                                                 sed_cmd = sed_cmd->next;
 826                                 if (!sed_cmd) bb_error_msg_and_die("unterminated {");
 827                                 continue;
 828                         }
 829
 830                         /* Okay, so did this line match? */
 831                         if (sed_cmd->invert ? !matched : matched) {
 832                                 /* Update last used regex in case a blank substitute BRE is found */
 833                                 if (sed_cmd->beg_match) {
 834                                         bbg.previous_regex_ptr = sed_cmd->beg_match;
 835                                 }
 836
 837                                 /* actual sedding */
 838                                 switch (sed_cmd->cmd) {
 839
 840                                 /* Print line number */
 841                                 case '=':
 842                                         fprintf(bbg.nonstdout, "%d\n", linenum);
 843                                         break;
 844
 845                                 /* Write the current pattern space up to the first newline */
 846                                 case 'P':
 847                                 {
 848                                         char *tmp = strchr(pattern_space, '\n');
 849
 850                                         if (tmp) {
 851                                                 *tmp = '\0';
 852                                                 sed_puts(pattern_space,1);
 853                                                 *tmp = '\n';
 854                                                 break;
 855                                         }
 856                                         /* Fall Through */
 857                                 }
 858
 859                                 /* Write the current pattern space to output */
 860                                 case 'p':
 861                                         sed_puts(pattern_space,no_newline);
 862                                         break;
 863                                 /* Delete up through first newline */
 864                                 case 'D':
 865                                 {
 866                                         char *tmp = strchr(pattern_space,'\n');
 867
 868                                         if (tmp) {
 869                                                 tmp = xstrdup(tmp+1);
 870                                                 free(pattern_space);
 871                                                 pattern_space = tmp;
 872                                                 goto restart;
 873                                         }
 874                                 }
 875                                 /* discard this line. */
 876                                 case 'd':
 877                                         goto discard_line;
 878
 879                                 /* Substitute with regex */
 880                                 case 's':
 881                                         if (do_subst_command(sed_cmd, &pattern_space)) {
 882                                                 substituted |= 1;
 883
 884                                                 /* handle p option */
 885                                                 if (sed_cmd->sub_p)
 886                                                         sed_puts(pattern_space,no_newline);
 887                                                 /* handle w option */
 888                                                 if (sed_cmd->file)
 889                                                         sed_cmd->no_newline = puts_maybe_newline(pattern_space, sed_cmd->file, sed_cmd->no_newline, no_newline);
 890
 891                                         }
 892                                         break;
 893
 894                                 /* Append line to linked list to be printed later */
 895                                 case 'a':
 896                                 {
 897                                         append(sed_cmd->string);
 898                                         break;
 899                                 }
 900
 901                                 /* Insert text before this line */
 902                                 case 'i':
 903                                         sed_puts(sed_cmd->string,1);
 904                                         break;
 905
 906                                 /* Cut and paste text (replace) */
 907                                 case 'c':
 908                                         /* Only triggers on last line of a matching range. */
 909                                         if (!sed_cmd->in_match)
 910                                                 sed_puts(sed_cmd->string,0);
 911                                         goto discard_line;
 912
 913                                 /* Read file, append contents to output */
 914                                 case 'r':
 915                                 {
 916                                         FILE *rfile;
 917
 918                                         rfile = fopen(sed_cmd->string, "r");
 919                                         if (rfile) {
 920                                                 char *line;
 921
 922                                                 while ((line = xmalloc_getline(rfile))
 923                                                                 != NULL)
 924                                                         append(line);
 925                                                 xprint_and_close_file(rfile);
 926                                         }
 927
 928                                         break;
 929                                 }
 930
 931                                 /* Write pattern space to file. */
 932                                 case 'w':
 933                                         sed_cmd->no_newline = puts_maybe_newline(pattern_space,sed_cmd->file, sed_cmd->no_newline,no_newline);
 934                                         break;
 935
 936                                 /* Read next line from input */
 937                                 case 'n':
 938                                         if (!bbg.be_quiet)
 939                                                 sed_puts(pattern_space,no_newline);
 940                                         if (next_line) {
 941                                                 free(pattern_space);
 942                                                 pattern_space = next_line;
 943                                                 no_newline = next_no_newline;
 944                                                 next_line = get_next_line(&next_no_newline);
 945                                                 linenum++;
 946                                                 break;
 947                                         }
 948                                         /* fall through */
 949
 950                                 /* Quit.  End of script, end of input. */
 951                                 case 'q':
 952                                         /* Exit the outer while loop */
 953                                         free(next_line);
 954                                         next_line = NULL;
 955                                         goto discard_commands;
 956
 957                                 /* Append the next line to the current line */
 958                                 case 'N':
 959                                 {
 960                                         /* If no next line, jump to end of script and exit. */
 961                                         if (next_line == NULL) {
 962                                                 /* Jump to end of script and exit */
 963                                                 free(next_line);
 964                                                 next_line = NULL;
 965                                                 goto discard_line;
 966                                         /* append next_line, read new next_line. */
 967                                         } else {
 968                                                 int len = strlen(pattern_space);
 969
 970                                                 pattern_space = realloc(pattern_space, len + strlen(next_line) + 2);
 971                                                 pattern_space[len] = '\n';
 972                                                 strcpy(pattern_space + len+1, next_line);
 973                                                 no_newline = next_no_newline;
 974                                                 next_line = get_next_line(&next_no_newline);
 975                                                 linenum++;
 976                                         }
 977                                         break;
 978                                 }
 979
 980                                 /* Test/branch if substitution occurred */
 981                                 case 't':
 982                                         if (!substituted) break;
 983                                         substituted = 0;
 984                                         /* Fall through */
 985                                 /* Test/branch if substitution didn't occur */
 986                                 case 'T':
 987                                         if (substituted) break;
 988                                         /* Fall through */
 989                                 /* Branch to label */
 990                                 case 'b':
 991                                         if (!sed_cmd->string) goto discard_commands;
 992                                         else sed_cmd = branch_to(sed_cmd->string);
 993                                         break;
 994                                 /* Transliterate characters */
 995                                 case 'y':
 996                                 {
 997                                         int i;
 998
 999                                         for (i = 0; pattern_space[i]; i++) {
1000                                                 int j;
1001
1002                                                 for (j = 0; sed_cmd->string[j]; j += 2) {
1003                                                         if (pattern_space[i] == sed_cmd->string[j]) {
1004                                                                 pattern_space[i] = sed_cmd->string[j + 1];
1005                                                                 break;
1006                                                         }
1007                                                 }
1008                                         }
1009
1010                                         break;
1011                                 }
1012                                 case 'g':       /* Replace pattern space with hold space */
1013                                         free(pattern_space);
1014                                         pattern_space = xstrdup(bbg.hold_space ? bbg.hold_space : "");
1015                                         break;
1016                                 case 'G':       /* Append newline and hold space to pattern space */
1017                                 {
1018                                         int pattern_space_size = 2;
1019                                         int hold_space_size = 0;
1020
1021                                         if (pattern_space)
1022                                                 pattern_space_size += strlen(pattern_space);
1023                                         if (bbg.hold_space)
1024                                                 hold_space_size = strlen(bbg.hold_space);
1025                                         pattern_space = xrealloc(pattern_space,
1026                                                         pattern_space_size + hold_space_size);
1027                                         if (pattern_space_size == 2)
1028                                                 pattern_space[0] = 0;
1029                                         strcat(pattern_space, "\n");
1030                                         if (bbg.hold_space)
1031                                                 strcat(pattern_space, bbg.hold_space);
1032                                         no_newline = 0;
1033
1034                                         break;
1035                                 }
1036                                 case 'h':       /* Replace hold space with pattern space */
1037                                         free(bbg.hold_space);
1038                                         bbg.hold_space = xstrdup(pattern_space);
1039                                         break;
1040                                 case 'H':       /* Append newline and pattern space to hold space */
1041                                 {
1042                                         int hold_space_size = 2;
1043                                         int pattern_space_size = 0;
1044
1045                                         if (bbg.hold_space)
1046                                                 hold_space_size += strlen(bbg.hold_space);
1047                                         if (pattern_space)
1048                                                 pattern_space_size = strlen(pattern_space);
1049                                         bbg.hold_space = xrealloc(bbg.hold_space,
1050                                                         hold_space_size + pattern_space_size);
1051
1052                                         if (hold_space_size == 2)
1053                                                 *bbg.hold_space = 0;
1054                                         strcat(bbg.hold_space, "\n");
1055                                         if (pattern_space)
1056                                                 strcat(bbg.hold_space, pattern_space);
1057
1058                                         break;
1059                                 }
1060                                 case 'x': /* Exchange hold and pattern space */
1061                                 {
1062                                         char *tmp = pattern_space;
1063                                         pattern_space = bbg.hold_space ? : xzalloc(1);
1064                                         no_newline = 0;
1065                                         bbg.hold_space = tmp;
1066                                         break;
1067                                 }
1068                                 }
1069                         }
1070                 }
1071
1072                 /*
1073                  * exit point from sedding...
1074                  */
1075 discard_commands:
1076                 /* we will print the line unless we were told to be quiet ('-n')
1077                    or if the line was suppressed (ala 'd'elete) */
1078                 if (!bbg.be_quiet) sed_puts(pattern_space,no_newline);
1079
1080                 /* Delete and such jump here. */
1081 discard_line:
1082                 flush_append();
1083                 free(pattern_space);
1084         }
1085 }
1086
1087 /* It is possible to have a command line argument with embedded
1088    newlines.  This counts as multiple command lines. */
1089
1090 static void add_cmd_block(char *cmdstr)
1091 {
1092         int go = 1;
1093         char *temp = xstrdup(cmdstr), *temp2 = temp;
1094
1095         while (go) {
1096                 int len = strcspn(temp2,"\n");
1097                 if (!temp2[len]) go = 0;
1098                 else temp2[len] = 0;
1099                 add_cmd(temp2);
1100                 temp2 += len+1;
1101         }
1102         free(temp);
1103 }
1104
1105 static void add_cmds_link(llist_t *opt_e)
1106 {
1107         if (!opt_e) return;
1108         add_cmds_link(opt_e->link);
1109         add_cmd_block(opt_e->data);
1110         free(opt_e);
1111 }
1112
1113 static void add_files_link(llist_t *opt_f)
1114 {
1115         char *line;
1116         FILE *cmdfile;
1117         if (!opt_f) return;
1118         add_files_link(opt_f->link);
1119         cmdfile = xfopen(opt_f->data, "r");
1120         while ((line = xmalloc_getline(cmdfile)) != NULL) {
1121                 add_cmd(line);
1122                 free(line);
1123         }
1124         xprint_and_close_file(cmdfile);
1125         free(opt_f);
1126 }
1127
1128 int sed_main(int argc, char **argv)
1129 {
1130         unsigned opt;
1131         llist_t *opt_e, *opt_f;
1132         int status = EXIT_SUCCESS;
1133
1134         bbg.sed_cmd_tail=&bbg.sed_cmd_head;
1135
1136         /* destroy command strings on exit */
1137         if (ENABLE_FEATURE_CLEAN_UP) atexit(sed_free_and_close_stuff);
1138
1139         /* Lie to autoconf when it starts asking stupid questions. */
1140         if (argc==2 && !strcmp(argv[1],"--version")) {
1141                 printf("This is not GNU sed version 4.0\n");
1142                 exit(0);
1143         }
1144
1145         /* do normal option parsing */
1146         opt_e = opt_f = NULL;
1147         opt_complementary = "e::f::"; /* can occur multiple times */
1148         opt = getopt32(argc, argv, "irne:f:", &opt_e, &opt_f);
1149         if (opt & 0x1) { // -i
1150                 bbg.in_place++;
1151                 atexit(cleanup_outname);
1152         }
1153         if (opt & 0x2) bbg.regex_type|=REG_EXTENDED; // -r
1154         if (opt & 0x4) bbg.be_quiet++; // -n
1155         if (opt & 0x8) { // -e
1156                 /* getopt32 reverses order of arguments, handle it */
1157                 add_cmds_link(opt_e);
1158         }
1159         if (opt & 0x10) { // -f
1160                 /* getopt32 reverses order of arguments, handle it */
1161                 add_files_link(opt_f);
1162         }
1163         /* if we didn't get a pattern from -e or -f, use argv[optind] */
1164         if (!(opt & 0x18)) {
1165                 if (argv[optind] == NULL)
1166                         bb_show_usage();
1167                 else
1168                         add_cmd_block(argv[optind++]);
1169         }
1170         /* Flush any unfinished commands. */
1171         add_cmd("");
1172
1173         /* By default, we write to stdout */
1174         bbg.nonstdout = stdout;
1175
1176         /* argv[(optind)..(argc-1)] should be names of file to process. If no
1177          * files were specified or '-' was specified, take input from stdin.
1178          * Otherwise, we process all the files specified. */
1179         if (argv[optind] == NULL) {
1180                 if (bbg.in_place)
1181                         bb_error_msg_and_die(bb_msg_requires_arg, "-i");
1182                 add_input_file(stdin);
1183                 process_files();
1184         } else {
1185                 int i;
1186                 FILE *file;
1187
1188                 for (i = optind; i < argc; i++) {
1189                         struct stat statbuf;
1190                         int nonstdoutfd;
1191
1192                         if (!strcmp(argv[i], "-") && !bbg.in_place) {
1193                                 add_input_file(stdin);
1194                                 process_files();
1195                                 continue;
1196                         }
1197                         file = fopen_or_warn(argv[i], "r");
1198                         if (!file) {
1199                                 status = EXIT_FAILURE;
1200                                 continue;
1201                         }
1202                         if (!bbg.in_place) {
1203                                 add_input_file(file);
1204                                 continue;
1205                         }
1206
1207                         bbg.outname = xasprintf("%sXXXXXX", argv[i]);
1208                         nonstdoutfd = mkstemp(bbg.outname);
1209                         if (-1 == nonstdoutfd)
1210                                 bb_error_msg_and_die("no temp file");
1211                         bbg.nonstdout = fdopen(nonstdoutfd,"w");
1212
1213                         /* Set permissions of output file */
1214
1215                         fstat(fileno(file),&statbuf);
1216                         fchmod(nonstdoutfd,statbuf.st_mode);
1217                         add_input_file(file);
1218                         process_files();
1219                         fclose(bbg.nonstdout);
1220
1221                         bbg.nonstdout = stdout;
1222                         /* unlink(argv[i]); */
1223                         // FIXME: error check / message?
1224                         rename(bbg.outname,argv[i]);
1225                         free(bbg.outname);
1226                         bbg.outname = 0;
1227                 }
1228                 if (bbg.input_file_count > bbg.current_input_file)
1229                         process_files();
1230         }
1231
1232         return status;
1233 }