* The previous version did not allow 4-digit octals.
*/
+//usage:#define echo_trivial_usage
+//usage: IF_FEATURE_FANCY_ECHO("[-neE] ") "[ARG]..."
+//usage:#define echo_full_usage "\n\n"
+//usage: "Print the specified ARGs to stdout"
+//usage: IF_FEATURE_FANCY_ECHO( "\n"
+//usage: "\n -n Suppress trailing newline"
+//usage: "\n -e Interpret backslash escapes (i.e., \\t=tab)"
+//usage: "\n -E Don't interpret backslash escapes (default)"
+//usage: )
+//usage:
+//usage:#define echo_example_usage
+//usage: "$ echo \"Erik is cool\"\n"
+//usage: "Erik is cool\n"
+//usage: IF_FEATURE_FANCY_ECHO("$ echo -e \"Erik\\nis\\ncool\"\n"
+//usage: "Erik\n"
+//usage: "is\n"
+//usage: "cool\n"
+//usage: "$ echo \"Erik\\nis\\ncool\"\n"
+//usage: "Erik\\nis\\ncool\n")
+
#include "libbb.h"
/* This is a NOFORK applet. Be very careful! */
/* NB: can be used by shell even if not enabled as applet */
+/*
+ * NB2: we don't use stdio, we need better error handing.
+ * Examples include writing into non-opened stdout and error on write.
+ *
+ * With stdio, output gets shoveled into stdout buffer, and even
+ * fflush cannot clear it out. It seems that even if libc receives
+ * EBADF on write attempts, it feels determined to output data no matter what.
+ * If echo is called by shell, it will try writing again later, and possibly
+ * will clobber future output. Not good.
+ *
+ * Solaris has fpurge which discards buffered input. glibc has __fpurge.
+ * But this function is not standard.
+ */
+
int echo_main(int argc UNUSED_PARAM, char **argv)
{
+ char **pp;
const char *arg;
+ char *out;
+ char *buffer;
+ unsigned buflen;
#if !ENABLE_FEATURE_FANCY_ECHO
enum {
eflag = '\\',
nflag = 1, /* 1 -- print '\n' */
};
- /* We must check that stdout is not closed.
- * The reason for this is highly non-obvious.
- * echo_main is used from shell. Shell must correctly handle "echo foo"
- * if stdout is closed. With stdio, output gets shoveled into
- * stdout buffer, and even fflush cannot clear it out. It seems that
- * even if libc receives EBADF on write attempts, it feels determined
- * to output data no matter what. So it will try later,
- * and possibly will clobber future output. Not good. */
-// TODO: check fcntl() & O_ACCMODE == O_WRONLY or O_RDWR?
- if (fcntl(1, F_GETFL) == -1)
- return 1; /* match coreutils 6.10 (sans error msg to stderr) */
- //if (dup2(1, 1) != 1) - old way
- // return 1;
-
- arg = *++argv;
- if (!arg)
- goto newline_ret;
+ argv++;
#else
- const char *p;
char nflag = 1;
char eflag = 0;
- /* We must check that stdout is not closed. */
- if (fcntl(1, F_GETFL) == -1)
- return 1;
+ while ((arg = *++argv) != NULL) {
+ char n, e;
- while (1) {
- arg = *++argv;
- if (!arg)
- goto newline_ret;
- if (*arg != '-')
- break;
+ if (arg[0] != '-')
+ break; /* not an option arg, echo it */
/* If it appears that we are handling options, then make sure
* that all of the options specified are actually valid.
* Otherwise, the string should just be echoed.
*/
- p = arg + 1;
- if (!*p) /* A single '-', so echo it. */
- goto just_echo;
-
+ arg++;
+ n = nflag;
+ e = eflag;
do {
- if (!strrchr("neE", *p))
+ if (*arg == 'n')
+ n = 0;
+ else if (*arg == 'e')
+ e = '\\';
+ else if (*arg != 'E') {
+ /* "-ccc" arg with one of c's invalid, echo it */
+ /* arg consisting from just "-" also handled here */
goto just_echo;
- } while (*++p);
-
- /* All of the options in this arg are valid, so handle them. */
- p = arg + 1;
- do {
- if (*p == 'n')
- nflag = 0;
- if (*p == 'e')
- eflag = '\\';
- } while (*++p);
+ }
+ } while (*++arg);
+ nflag = n;
+ eflag = e;
}
just_echo:
#endif
- while (1) {
- /* arg is already == *argv and isn't NULL */
+
+ buflen = 0;
+ pp = argv;
+ while ((arg = *pp) != NULL) {
+ buflen += strlen(arg) + 1;
+ pp++;
+ }
+ out = buffer = xmalloc(buflen + 1); /* +1 is needed for "no args" case */
+
+ while ((arg = *argv) != NULL) {
int c;
if (!eflag) {
/* optimization for very common case */
- fputs(arg, stdout);
- } else while ((c = *arg++)) {
- if (c == eflag) { /* Check for escape seq. */
+ out = stpcpy(out, arg);
+ } else
+ while ((c = *arg++) != '\0') {
+ if (c == eflag) {
+ /* This is an "\x" sequence */
+
if (*arg == 'c') {
- /* '\c' means cancel newline and
+ /* "\c" means cancel newline and
* ignore all subsequent chars. */
- goto ret;
+ goto do_write;
}
-#if !ENABLE_FEATURE_FANCY_ECHO
- /* SUSv3 specifies that octal escapes must begin with '0'. */
- if ( ((int)(unsigned char)(*arg) - '0') >= 8) /* '8' or bigger */
-#endif
- {
- /* Since SUSv3 mandates a first digit of 0, 4-digit octals
- * of the form \0### are accepted. */
- if (*arg == '0') {
- /* NB: don't turn "...\0" into "...\" */
- if (arg[1] && ((unsigned char)(arg[1]) - '0') < 8) {
- arg++;
- }
+ /* Since SUSv3 mandates a first digit of 0, 4-digit octals
+ * of the form \0### are accepted. */
+ if (*arg == '0') {
+ if ((unsigned char)(arg[1] - '0') < 8) {
+ /* 2nd char is 0..7: skip leading '0' */
+ arg++;
}
- /* bb_process_escape_sequence handles NUL correctly
- * ("...\" case). */
- c = bb_process_escape_sequence(&arg);
+ }
+ /* bb_process_escape_sequence handles NUL correctly
+ * ("...\" case). */
+ {
+ /* optimization: don't force arg to be on-stack,
+ * use another variable for that. ~30 bytes win */
+ const char *z = arg;
+ c = bb_process_escape_sequence(&z);
+ arg = z;
}
}
- bb_putchar(c);
+ *out++ = c;
}
- arg = *++argv;
- if (!arg)
+ if (!*++argv)
break;
- bb_putchar(' ');
+ *out++ = ' ';
}
- newline_ret:
if (nflag) {
- bb_putchar('\n');
+ *out++ = '\n';
}
- ret:
- return fflush_all();
+
+ do_write:
+ /* Careful to error out on partial writes too (think ENOSPC!) */
+ errno = 0;
+ /*r =*/ full_write(STDOUT_FILENO, buffer, out - buffer);
+ free(buffer);
+ if (/*WRONG:r < 0*/ errno) {
+ bb_perror_msg(bb_msg_write_error);
+ return 1;
+ }
+ return 0;
}
-/*-
+/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
goto just_echo;
do {
- if (!strrchr("neE", *p))
+ if (!strchr("neE", *p))
goto just_echo;
} while (*++p);
/* optimization for very common case */
p += strlen(arg);
} else while ((c = *arg++)) {
- if (c == eflag) { /* Check for escape seq. */
+ if (c == eflag) {
+ /* This is an "\x" sequence */
+
if (*arg == 'c') {
- /* '\c' means cancel newline and
+ /* "\c" means cancel newline and
* ignore all subsequent chars. */
cur_io->iov_len = p - (char*)cur_io->iov_base;
cur_io++;
goto ret;
}
-#if !ENABLE_FEATURE_FANCY_ECHO
- /* SUSv3 specifies that octal escapes must begin with '0'. */
- if ( (((unsigned char)*arg) - '1') >= 7)
-#endif
- {
- /* Since SUSv3 mandates a first digit of 0, 4-digit octals
- * of the form \0### are accepted. */
- if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
- arg++;
- }
- /* bb_process_escape_sequence can handle nul correctly */
- c = bb_process_escape_sequence( (void*) &arg);
+ /* Since SUSv3 mandates a first digit of 0, 4-digit octals
+ * of the form \0### are accepted. */
+ if (*arg == '0' && (unsigned char)(arg[1] - '0') < 8) {
+ arg++;
}
+ /* bb_process_escape_sequence can handle nul correctly */
+ c = bb_process_escape_sequence( (void*) &arg);
}
*p++ = c;
}
projects / platform / upstream / busybox.git / blobdiff