1 /* tr -- a filter to translate characters
2 Copyright (C) 1991, 1995 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
18 /* Written by Jim Meyering, meyering@cs.utexas.edu. */
22 /* Get isblank from GNU libc. */
28 #include <sys/types.h>
36 #define ULONG_MAX ((unsigned long) ~(unsigned long) 0)
40 #define LONG_MAX ((long int) (ULONG_MAX >> 1))
44 #define UCHAR_MAX 0xFF
47 #define N_CHARS (UCHAR_MAX + 1)
49 /* A pointer to a function that returns an int. */
50 typedef int (*PFI) ();
52 /* Convert from character C to its index in the collating
53 sequence array. Just cast to an unsigned int to avoid
54 problems with sign-extension. */
55 #define ORD(c) (unsigned int)(c)
57 /* The inverse of ORD. */
58 #define CHR(i) (unsigned char)(i)
60 /* The value for Spec_list->state that indicates to
61 get_next that it should initialize the tail pointer.
62 Its value doesn't matter as long as it can't be
63 confused with a valid character code. */
64 #define BEGIN_STATE (2 * N_CHARS)
66 /* The value for Spec_list->state that indicates to
67 get_next that the element pointed to by Spec_list->tail is
68 being considered for the first time on this pass through the
69 list -- it indicates that get_next should make any necessary
71 #define NEW_ELEMENT (BEGIN_STATE + 1)
73 /* A value distinct from any character that may have been stored in a
74 buffer as the result of a block-read in the function squeeze_filter. */
75 #define NOT_A_CHAR (unsigned int)(-1)
77 /* The following (but not CC_NO_CLASS) are indices into the array of
78 valid character class strings. */
81 CC_ALNUM = 0, CC_ALPHA = 1, CC_BLANK = 2, CC_CNTRL = 3,
82 CC_DIGIT = 4, CC_GRAPH = 5, CC_LOWER = 6, CC_PRINT = 7,
83 CC_PUNCT = 8, CC_SPACE = 9, CC_UPPER = 10, CC_XDIGIT = 11,
87 /* Character class to which a character (returned by get_next) belonged;
88 but it is set only if the construct from which the character was obtained
89 was one of the character classes [:upper:] or [:lower:]. The value
90 is used only when translating and then, only to make sure that upper
91 and lower class constructs have the same relative positions in string1
93 enum Upper_Lower_class
100 /* A shortcut to ensure that when constructing the translation array,
101 one of the values returned by paired calls to get_next (from s1 and s2)
102 is from [:upper:] and the other is from [:lower:], or neither is from
103 upper or lower. In fact, no other character classes are allowed when
104 translating, but that condition is tested elsewhere. This array is
105 indexed by values of type enum Upper_Lower_class. */
106 static int const class_ok[3][3] =
113 /* The type of a List_element. See build_spec_list for more details. */
114 enum Range_element_type
124 /* One construct in one of tr's argument strings.
125 For example, consider the POSIX version of the classic tr command:
126 tr -cs 'a-zA-Z_' '[\n*]'
127 String1 has 3 constructs, two of which are ranges (a-z and A-Z),
128 and a single normal character, `_'. String2 has one construct. */
131 enum Range_element_type type;
132 struct List_element *next;
138 unsigned int first_char;
139 unsigned int last_char;
142 enum Char_class char_class;
146 unsigned int the_repeated_char;
154 /* Each of tr's argument strings is parsed into a form that is easier
155 to work with: a linked list of constructs (struct List_element).
156 Each Spec_list structure also encapsulates various attributes of
157 the corresponding argument string. The attributes are used mainly
158 to verify that the strings are valid in the context of any options
159 specified (like -s, -d, or -c). The main exception is the member
160 `tail', which is first used to construct the list. After construction,
161 it is used by get_next to save its state when traversing the list.
162 The member `state' serves a similar function. */
165 /* Points to the head of the list of range elements.
166 The first struct is a dummy; its members are never used. */
167 struct List_element *head;
169 /* When appending, points to the last element. When traversing via
170 get_next(), points to the element to process next. Setting
171 Spec_list.state to the value BEGIN_STATE before calling get_next
172 signals get_next to initialize tail to point to head->next. */
173 struct List_element *tail;
175 /* Used to save state between calls to get_next(). */
178 /* Length, in the sense that length('a-z[:digit:]123abc')
179 is 42 ( = 26 + 10 + 6). */
182 /* The number of [c*] and [c*0] constructs that appear in this spec. */
183 int n_indefinite_repeats;
185 /* Non-zero if this spec contains at least one equivalence
186 class construct e.g. [=c=]. */
189 /* Non-zero if this spec contains at least one of [:upper:] or
190 [:lower:] class constructs. */
191 int has_upper_or_lower;
193 /* Non-zero if this spec contains at least one of the character class
194 constructs (all but upper and lower) that aren't allowed in s2. */
195 int has_restricted_char_class;
202 /* The name by which this program was run. */
205 /* When non-zero, each sequence in the input of a repeated character
206 (call it c) is replaced (in the output) by a single occurrence of c
207 for every c in the squeeze set. */
208 static int squeeze_repeats = 0;
210 /* When non-zero, removes characters in the delete set from input. */
211 static int delete = 0;
213 /* Use the complement of set1 in place of set1. */
214 static int complement = 0;
216 /* When non-zero, this flag causes GNU tr to provide strict
217 compliance with POSIX draft 1003.2.11.2. The POSIX spec
218 says that when -d is used without -s, string2 (if present)
219 must be ignored. Silently ignoring arguments is a bad idea.
220 The default GNU behavior is to give a usage message and exit.
221 Additionally, when this flag is non-zero, tr prints warnings
222 on stderr if it is being used in a manner that is not portable.
223 Applicable warnings are given by default, but are suppressed
224 if the environment variable `POSIXLY_CORRECT' is set, since
225 being POSIX conformant means we can't issue such messages.
226 Warnings on the following topics are suppressed when this
227 variable is non-zero:
228 1. Ambiguous octal escapes. */
229 static int posix_pedantic;
231 /* When tr is performing translation and string1 is longer than string2,
232 POSIX says that the result is undefined. That gives the implementor
233 of a POSIX conforming version of tr two reasonable choices for the
234 semantics of this case.
236 * The BSD tr pads string2 to the length of string1 by
237 repeating the last character in string2.
239 * System V tr ignores characters in string1 that have no
240 corresponding character in string2. That is, string1 is effectively
241 truncated to the length of string2.
243 When non-zero, this flag causes GNU tr to imitate the behavior
244 of System V tr when translating with string1 longer than string2.
245 The default is to emulate BSD tr. This flag is ignored in modes where
246 no translation is performed. Emulating the System V tr
247 in this exceptional case causes the relatively common BSD idiom:
249 tr -cs A-Za-z0-9 '\012'
251 to break (it would convert only zero bytes, rather than all
252 non-alphanumerics, to newlines).
254 WARNING: This switch does not provide general BSD or System V
255 compatibility. For example, it doesn't disable the interpretation
256 of the POSIX constructs [:alpha:], [=c=], and [c*10], so if by
257 some unfortunate coincidence you use such constructs in scripts
258 expecting to use some other version of tr, the scripts will break. */
259 static int truncate_set1 = 0;
261 /* An alias for (!delete && non_option_args == 2).
262 It is set in main and used there and in validate(). */
263 static int translating;
269 #define IO_BUF_SIZE BUFSIZ
270 static unsigned char io_buf[IO_BUF_SIZE];
272 static char const *const char_class_name[] =
274 "alnum", "alpha", "blank", "cntrl", "digit", "graph",
275 "lower", "print", "punct", "space", "upper", "xdigit"
277 #define N_CHAR_CLASSES (sizeof(char_class_name) / sizeof(char_class_name[0]))
279 typedef char SET_TYPE;
281 /* Array of boolean values. A character `c' is a member of the
282 squeeze set if and only if in_squeeze_set[c] is true. The squeeze
283 set is defined by the last (possibly, the only) string argument
284 on the command line when the squeeze option is given. */
285 static SET_TYPE in_squeeze_set[N_CHARS];
287 /* Array of boolean values. A character `c' is a member of the
288 delete set if and only if in_delete_set[c] is true. The delete
289 set is defined by the first (or only) string argument on the
290 command line when the delete option is given. */
291 static SET_TYPE in_delete_set[N_CHARS];
293 /* Array of character values defining the translation (if any) that
294 tr is to perform. Translation is performed only when there are
295 two specification strings and the delete switch is not given. */
296 static char xlate[N_CHARS];
298 /* If non-zero, display usage information and exit. */
299 static int show_help;
301 /* If non-zero, print the version on standard output then exit. */
302 static int show_version;
304 static struct option const long_options[] =
306 {"complement", no_argument, NULL, 'c'},
307 {"delete", no_argument, NULL, 'd'},
308 {"squeeze-repeats", no_argument, NULL, 's'},
309 {"truncate-set1", no_argument, NULL, 't'},
310 {"help", no_argument, &show_help, 1},
311 {"version", no_argument, &show_version, 1},
320 fprintf (stderr, "Try `%s --help' for more information.\n",
325 Usage: %s [OPTION]... SET1 [SET2]\n\
330 -c, --complement first complement SET1\n\
331 -d, --delete delete characters in SET1, do not translate\n\
332 -s, --squeeze-repeats replace sequence of characters with one\n\
333 -t, --truncate-set1 first truncate SET1 to length of SET2\n\
334 --help display this help and exit\n\
335 --version output version information and exit\n\
339 SETs are specified as strings of characters. Most represent\n\
340 themselves. Here are the special writings:\n\
342 \\NNN character with octal value NNN (1 to 3 octal digits)\n\
349 \\t horizontal tab\n\
351 CHAR1-CHAR2 all characters from CHAR1 to CHAR2 in ascending order\n\
352 [CHAR1-CHAR2] same as CHAR1-CHAR2, if both SET1 and SET2 use this\n\
353 [CHAR*] in SET2, copies of CHAR until length of SET1\n\
354 [CHAR*REPEAT] REPEAT copies of CHAR, REPEAT octal if starting with 0\n\
355 [:alnum:] all letters and digits\n\
356 [:alpha:] all letters\n\
357 [:blank:] all horizontal whitespace\n\
358 [:cntrl:] all control characters\n\
359 [:digit:] all digits\n\
360 [:graph:] all printable characters, not including space\n\
361 [:lower:] all lower case letters\n\
362 [:print:] all printable characters, including space\n\
363 [:punct:] all punctuation characters\n\
364 [:space:] all horizontal or vertical whitespace\n\
365 [:upper:] all upper case letters\n\
366 [:xdigit:] all hexadecimal digits\n\
367 [=CHAR=] all characters which are equivalent to CHAR\n\
371 Translation occurs if -d is not given and both SET1 and SET2 appear.\n\
372 -t may be used only when translating. SET2 is extended to length of\n\
373 SET1 by repeating its last character as necessary. Excess characters\n\
374 of SET2 are ignored. Only [:lower:] and [:upper:] are guaranteed to\n\
375 expand in ascending order; used in SET2 while translating, they may\n\
376 only be used in pairs to specify case conversion. -s uses SET1 if not\n\
377 translating nor deleting; else squeezing uses SET2 and occurs after\n\
378 translation or deletion.\n\
384 /* Return non-zero if the character C is a member of the
385 equivalence class containing the character EQUIV_CLASS. */
388 is_equiv_class_member (equiv_class, c)
389 unsigned int equiv_class;
392 return (equiv_class == c);
395 /* Return non-zero if the character C is a member of the
396 character class CHAR_CLASS. */
399 is_char_class_member (char_class, c)
400 enum Char_class char_class;
447 /* Perform the first pass over each range-spec argument S, converting all
448 \c and \ddd escapes to their one-byte representations. The conversion
449 is done in-place, so S must point to writable storage. If an invalid
450 quote sequence is found print an error message and return non-zero.
451 Otherwise set *LEN to the length of the resulting string and return
452 zero. The resulting array of characters may contain zero-bytes;
453 however, on input, S is assumed to be null-terminated, and hence
454 cannot contain actual (non-escaped) zero bytes. */
464 for (i = 0; s[i]; i++)
506 oct_digit = s[i + 2] - '0';
507 if (0 <= oct_digit && oct_digit <= 7)
509 c = 8 * c + oct_digit;
511 oct_digit = s[i + 2] - '0';
512 if (0 <= oct_digit && oct_digit <= 7)
514 if (8 * c + oct_digit < N_CHARS)
516 c = 8 * c + oct_digit;
519 else if (!posix_pedantic)
521 /* Any octal number larger than 0377 won't
522 fit in 8 bits. So we stop when adding the
523 next digit would put us over the limit and
524 give a warning about the ambiguity. POSIX
525 isn't clear on this, but one person has said
526 that in his interpretation, POSIX says tr
527 can't even give a warning. */
528 error (0, 0, "warning: the ambiguous octal escape \
529 \\%c%c%c is being\n\tinterpreted as the 2-byte sequence \\0%c%c, `%c'",
530 s[i], s[i + 1], s[i + 2],
531 s[i], s[i + 1], s[i + 2]);
537 error (0, 0, "invalid backslash escape at end of string");
541 error (0, 0, "invalid backslash escape `\\%c'", s[i + 1]);
557 /* If CLASS_STR is a valid character class string, return its index
558 in the global char_class_name array. Otherwise, return CC_NO_CLASS. */
560 static enum Char_class
561 look_up_char_class (class_str)
562 unsigned char *class_str;
566 for (i = 0; i < N_CHAR_CLASSES; i++)
567 if (strcmp ((const char *) class_str, char_class_name[i]) == 0)
568 return (enum Char_class) i;
572 /* Return a newly allocated string with a printable version of C.
573 This function is used solely for formatting error messages. */
576 make_printable_char (c)
579 char *buf = xmalloc (5);
581 assert (c < N_CHARS);
589 sprintf (buf, "\\%03o", c);
594 /* Return a newly allocated copy of S which is suitable for printing.
595 LEN is the number of characters in S. Most non-printing
596 (isprint) characters are represented by a backslash followed by
597 3 octal digits. However, the characters represented by \c escapes
598 where c is one of [abfnrtv] are represented by their 2-character \c
599 sequences. This function is used solely for printing error messages. */
602 make_printable_str (s, len)
603 const unsigned char *s;
606 /* Worst case is that every character expands to a backslash
607 followed by a 3-character octal escape sequence. */
608 char *printable_buf = xmalloc (4 * len + 1);
609 char *p = printable_buf;
612 for (i = 0; i < len; i++)
650 sprintf (buf, "\\%03o", s[i]);
656 return printable_buf;
659 /* Append a newly allocated structure representing a
660 character C to the specification list LIST. */
663 append_normal_char (list, c)
664 struct Spec_list *list;
667 struct List_element *new;
669 new = (struct List_element *) xmalloc (sizeof (struct List_element));
671 new->type = RE_NORMAL_CHAR;
672 new->u.normal_char = c;
674 list->tail->next = new;
678 /* Append a newly allocated structure representing the range
679 of characters from FIRST to LAST to the specification list LIST.
680 Return non-zero if LAST precedes FIRST in the collating sequence,
681 zero otherwise. This means that '[c-c]' is acceptable. */
684 append_range (list, first, last)
685 struct Spec_list *list;
689 struct List_element *new;
691 if (ORD (first) > ORD (last))
693 char *tmp1 = make_printable_char (first);
694 char *tmp2 = make_printable_char (last);
697 "range-endpoints of `%s-%s' are in reverse collating sequence order",
703 new = (struct List_element *) xmalloc (sizeof (struct List_element));
705 new->type = RE_RANGE;
706 new->u.range.first_char = first;
707 new->u.range.last_char = last;
709 list->tail->next = new;
714 /* If CHAR_CLASS_STR is a valid character class string, append a
715 newly allocated structure representing that character class to the end
716 of the specification list LIST and return 0. If CHAR_CLASS_STR is not
717 a valid string, print an error message and return non-zero. */
720 append_char_class (list, char_class_str, len)
721 struct Spec_list *list;
722 unsigned char *char_class_str;
725 enum Char_class char_class;
726 struct List_element *new;
728 char_class = look_up_char_class (char_class_str);
729 if (char_class == CC_NO_CLASS)
731 char *tmp = make_printable_str (char_class_str, len);
733 error (0, 0, "invalid character class `%s'", tmp);
737 new = (struct List_element *) xmalloc (sizeof (struct List_element));
739 new->type = RE_CHAR_CLASS;
740 new->u.char_class = char_class;
742 list->tail->next = new;
747 /* Append a newly allocated structure representing a [c*n]
748 repeated character construct to the specification list LIST.
749 THE_CHAR is the single character to be repeated, and REPEAT_COUNT
750 is a non-negative repeat count. */
753 append_repeated_char (list, the_char, repeat_count)
754 struct Spec_list *list;
755 unsigned int the_char;
756 long int repeat_count;
758 struct List_element *new;
760 new = (struct List_element *) xmalloc (sizeof (struct List_element));
762 new->type = RE_REPEATED_CHAR;
763 new->u.repeated_char.the_repeated_char = the_char;
764 new->u.repeated_char.repeat_count = repeat_count;
766 list->tail->next = new;
770 /* Given a string, EQUIV_CLASS_STR, from a [=str=] context and
771 the length of that string, LEN, if LEN is exactly one, append
772 a newly allocated structure representing the specified
773 equivalence class to the specification list, LIST and return zero.
774 If LEN is not 1, issue an error message and return non-zero. */
777 append_equiv_class (list, equiv_class_str, len)
778 struct Spec_list *list;
779 unsigned char *equiv_class_str;
782 struct List_element *new;
786 char *tmp = make_printable_str (equiv_class_str, len);
788 error (0, 0, "%s: equivalence class operand must be a single character",
793 new = (struct List_element *) xmalloc (sizeof (struct List_element));
795 new->type = RE_EQUIV_CLASS;
796 new->u.equiv_code = *equiv_class_str;
798 list->tail->next = new;
803 /* Return a newly allocated copy of the substring P[FIRST_IDX..LAST_IDX].
804 The returned string has length LAST_IDX - FIRST_IDX + 1, may contain
805 NUL bytes, and is not NUL-terminated. */
807 static unsigned char *
808 substr (p, first_idx, last_idx)
809 const unsigned char *p;
813 int len = last_idx - first_idx + 1;
814 unsigned char *tmp = (unsigned char *) xmalloc (len);
816 assert (first_idx <= last_idx);
817 /* Use memcpy rather than strncpy because `p' may contain zero-bytes. */
818 memcpy (tmp, p + first_idx, len);
822 /* Search forward starting at START_IDX for the 2-char sequence
823 (PRE_BRACKET_CHAR,']') in the string P of length P_LEN. If such
824 a sequence is found, return the index of the first character,
825 otherwise return -1. P may contain zero bytes. */
828 find_closing_delim (p, start_idx, p_len, pre_bracket_char)
829 const unsigned char *p;
832 unsigned int pre_bracket_char;
836 for (i = start_idx; i < p_len - 1; i++)
837 if (p[i] == pre_bracket_char && p[i + 1] == ']')
842 /* Convert a string S with explicit length LEN, possibly
843 containing embedded zero bytes, to a long integer value.
844 If the string represents a negative value, a value larger
845 than LONG_MAX, or if all LEN characters do not represent a
846 valid integer, return non-zero and do not modify *VAL.
847 Otherwise, return zero and set *VAL to the converted value. */
850 non_neg_strtol (s, len, val)
851 const unsigned char *s;
863 else if (ISDIGIT (s[0]))
868 for (i = 0; i < len; i++)
872 if (c >= base || c < 0)
874 if (i > 8 && sum > (LONG_MAX - c) / base)
876 sum = sum * base + c;
882 /* Parse the bracketed repeat-char syntax. If the P_LEN characters
883 beginning with P[ START_IDX ] comprise a valid [c*n] construct,
884 return the character and the repeat count through the arg pointers,
885 CHAR_TO_REPEAT and N, and then return the index of the closing
886 bracket as the function value. If the second character following
887 the opening bracket is not `*' or if no closing bracket can be
888 found, return -1. If a closing bracket is found and the
889 second char is `*', but the string between the `*' and `]' isn't
890 empty, an octal number, or a decimal number, print an error message
894 find_bracketed_repeat (p, start_idx, p_len, char_to_repeat, n)
895 const unsigned char *p;
898 unsigned int *char_to_repeat;
903 assert (start_idx + 1 < p_len);
904 if (p[start_idx + 1] != '*')
907 for (i = start_idx + 2; i < p_len; i++)
911 const unsigned char *digit_str;
912 int digit_str_len = i - start_idx - 2;
914 *char_to_repeat = p[start_idx];
915 if (digit_str_len == 0)
917 /* We've matched [c*] -- no explicit repeat count. */
922 /* Here, we have found [c*s] where s should be a string
923 of octal or decimal digits. */
924 digit_str = &p[start_idx + 2];
925 if (non_neg_strtol (digit_str, digit_str_len, n))
927 char *tmp = make_printable_str (digit_str, digit_str_len);
928 error (0, 0, "invalid repeat count `%s' in [c*n] construct", tmp);
935 return -1; /* No bracket found. */
938 /* Convert string UNESACPED_STRING (which has been preprocessed to
939 convert backslash-escape sequences) of length LEN characters into
940 a linked list of the following 5 types of constructs:
941 - [:str:] Character class where `str' is one of the 12 valid strings.
942 - [=c=] Equivalence class where `c' is any single character.
943 - [c*n] Repeat the single character `c' `n' times. n may be omitted.
944 However, if `n' is present, it must be a non-negative octal or
946 - r-s Range of characters from `r' to `s'. The second endpoint must
947 not precede the first in the current collating sequence.
948 - c Any other character is interpreted as itself. */
951 build_spec_list (unescaped_string, len, result)
952 const unsigned char *unescaped_string;
954 struct Spec_list *result;
956 const unsigned char *p;
959 p = unescaped_string;
961 /* The main for-loop below recognizes the 4 multi-character constructs.
962 A character that matches (in its context) none of the multi-character
963 constructs is classified as `normal'. Since all multi-character
964 constructs have at least 3 characters, any strings of length 2 or
965 less are composed solely of normal characters. Hence, the index of
966 the outer for-loop runs only as far as LEN-2. */
968 for (i = 0; i < len - 2;)
977 int closing_delim_idx;
978 int closing_bracket_idx;
979 unsigned int char_to_repeat;
983 closing_delim_idx = find_closing_delim (p, i + 2, len, p[i + 1]);
984 if (closing_delim_idx >= 0)
987 unsigned char *opnd_str = substr (p, i + 2,
988 closing_delim_idx - 1);
990 parse_failed = append_char_class (result, opnd_str,
991 (closing_delim_idx - 1) - (i + 2) + 1);
993 parse_failed = append_equiv_class (result, opnd_str,
994 (closing_delim_idx - 1) - (i + 2) + 1);
997 /* Return non-zero if append_*_class reports a problem. */
1001 i = closing_delim_idx + 2;
1004 /* Else fall through. This could be [:*] or [=*]. */
1006 /* Determine whether this is a bracketed repeat range
1007 matching the RE \[.\*(dec_or_oct_number)?\]. */
1008 closing_bracket_idx = find_bracketed_repeat (p, i + 1,
1009 len, &char_to_repeat, &repeat_count);
1010 if (closing_bracket_idx >= 0)
1012 append_repeated_char (result, char_to_repeat, repeat_count);
1013 i = closing_bracket_idx + 1;
1016 else if (closing_bracket_idx == -1)
1021 /* Found a string that looked like [c*n] but the
1022 numeric part was invalid. */
1029 /* Here if we've tried to match [c*n], [:str:], and [=c=]
1030 and none of them fit. So we still have to consider the
1031 range `[-c' (from `[' to `c'). */
1033 /* Look ahead one char for ranges like a-z. */
1034 if (p[i + 1] == '-')
1036 if (append_range (result, p[i], p[i + 2]))
1042 append_normal_char (result, p[i]);
1049 /* Now handle the (2 or fewer) remaining characters p[i]..p[len - 1]. */
1050 for (; i < len; i++)
1051 append_normal_char (result, p[i]);
1056 /* Given a Spec_list S (with its saved state implicit in the values
1057 of its members `tail' and `state'), return the next single character
1058 in the expansion of S's constructs. If the last character of S was
1059 returned on the previous call or if S was empty, this function
1060 returns -1. For example, successive calls to get_next where S
1061 represents the spec-string 'a-d[y*3]' will return the sequence
1062 of values a, b, c, d, y, y, y, -1. Finally, if the construct from
1063 which the returned character comes is [:upper:] or [:lower:], the
1064 parameter CLASS is given a value to indicate which it was. Otherwise
1065 CLASS is set to UL_NONE. This value is used only when constructing
1066 the translation table to verify that any occurrences of upper and
1067 lower class constructs in the spec-strings appear in the same relative
1072 struct Spec_list *s;
1073 enum Upper_Lower_class *class;
1075 struct List_element *p;
1082 if (s->state == BEGIN_STATE)
1084 s->tail = s->head->next;
1085 s->state = NEW_ELEMENT;
1094 case RE_NORMAL_CHAR:
1095 return_val = p->u.normal_char;
1096 s->state = NEW_ELEMENT;
1101 if (s->state == NEW_ELEMENT)
1102 s->state = ORD (p->u.range.first_char);
1105 return_val = CHR (s->state);
1106 if (s->state == ORD (p->u.range.last_char))
1109 s->state = NEW_ELEMENT;
1114 if (s->state == NEW_ELEMENT)
1116 for (i = 0; i < N_CHARS; i++)
1117 if (is_char_class_member (p->u.char_class, i))
1119 assert (i < N_CHARS);
1122 assert (is_char_class_member (p->u.char_class, s->state));
1123 return_val = CHR (s->state);
1124 for (i = s->state + 1; i < N_CHARS; i++)
1125 if (is_char_class_member (p->u.char_class, i))
1132 s->state = NEW_ELEMENT;
1136 switch (p->u.char_class)
1151 case RE_EQUIV_CLASS:
1152 /* FIXME: this assumes that each character is alone in its own
1153 equivalence class (which appears to be correct for my
1154 LC_COLLATE. But I don't know of any function that allows
1155 one to determine a character's equivalence class. */
1157 return_val = p->u.equiv_code;
1158 s->state = NEW_ELEMENT;
1162 case RE_REPEATED_CHAR:
1163 /* Here, a repeat count of n == 0 means don't repeat at all. */
1164 assert (p->u.repeated_char.repeat_count >= 0);
1165 if (p->u.repeated_char.repeat_count == 0)
1168 s->state = NEW_ELEMENT;
1169 return_val = get_next (s, class);
1173 if (s->state == NEW_ELEMENT)
1178 return_val = p->u.repeated_char.the_repeated_char;
1179 if (p->u.repeated_char.repeat_count > 0
1180 && s->state == p->u.repeated_char.repeat_count)
1183 s->state = NEW_ELEMENT;
1200 /* This is a minor kludge. This function is called from
1201 get_spec_stats to determine the cardinality of a set derived
1202 from a complemented string. It's a kludge in that some of the
1203 same operations are (duplicated) performed in set_initialize. */
1206 card_of_complement (s)
1207 struct Spec_list *s;
1210 int cardinality = N_CHARS;
1211 SET_TYPE in_set[N_CHARS];
1213 memset (in_set, 0, N_CHARS * sizeof (in_set[0]));
1214 s->state = BEGIN_STATE;
1215 while ((c = get_next (s, NULL)) != -1)
1221 /* Gather statistics about the spec-list S in preparation for the tests
1222 in validate that determine the consistency of the specs. This function
1223 is called at most twice; once for string1, and again for any string2.
1224 LEN_S1 < 0 indicates that this is the first call and that S represents
1225 string1. When LEN_S1 >= 0, it is the length of the expansion of the
1226 constructs in string1, and we can use its value to resolve any
1227 indefinite repeat construct in S (which represents string2). Hence,
1228 this function has the side-effect that it converts a valid [c*]
1229 construct in string2 to [c*n] where n is large enough (or 0) to give
1230 string2 the same length as string1. For example, with the command
1231 tr a-z 'A[\n*]Z' on the second call to get_spec_stats, LEN_S1 would
1232 be 26 and S (representing string2) would be converted to 'A[\n*24]Z'. */
1235 get_spec_stats (s, len_s1)
1236 struct Spec_list *s;
1239 struct List_element *p;
1240 struct List_element *indefinite_repeat_element = NULL;
1243 s->n_indefinite_repeats = 0;
1244 s->has_equiv_class = 0;
1245 s->has_restricted_char_class = 0;
1246 s->has_upper_or_lower = 0;
1247 for (p = s->head->next; p; p = p->next)
1252 case RE_NORMAL_CHAR:
1257 assert (p->u.range.last_char >= p->u.range.first_char);
1258 len += p->u.range.last_char - p->u.range.first_char + 1;
1262 for (i = 0; i < N_CHARS; i++)
1263 if (is_char_class_member (p->u.char_class, i))
1265 switch (p->u.char_class)
1269 s->has_upper_or_lower = 1;
1272 s->has_restricted_char_class = 1;
1277 case RE_EQUIV_CLASS:
1278 for (i = 0; i < N_CHARS; i++)
1279 if (is_equiv_class_member (p->u.equiv_code, i))
1281 s->has_equiv_class = 1;
1284 case RE_REPEATED_CHAR:
1285 if (p->u.repeated_char.repeat_count > 0)
1286 len += p->u.repeated_char.repeat_count;
1287 else if (p->u.repeated_char.repeat_count == 0)
1289 indefinite_repeat_element = p;
1290 ++(s->n_indefinite_repeats);
1300 if (len_s1 >= len && s->n_indefinite_repeats == 1)
1302 indefinite_repeat_element->u.repeated_char.repeat_count = len_s1 - len;
1305 if (complement && len_s1 < 0)
1306 s->length = card_of_complement (s);
1313 spec_init (spec_list)
1314 struct Spec_list *spec_list;
1316 spec_list->head = spec_list->tail =
1317 (struct List_element *) xmalloc (sizeof (struct List_element));
1318 spec_list->head->next = NULL;
1321 /* This function makes two passes over the argument string S. The first
1322 one converts all \c and \ddd escapes to their one-byte representations.
1323 The second constructs a linked specification list, SPEC_LIST, of the
1324 characters and constructs that comprise the argument string. If either
1325 of these passes detects an error, this function returns non-zero. */
1328 parse_str (s, spec_list)
1330 struct Spec_list *spec_list;
1334 if (unquote (s, &len))
1336 if (build_spec_list (s, len, spec_list))
1341 /* Given two specification lists, S1 and S2, and assuming that
1342 S1->length > S2->length, append a single [c*n] element to S2 where c
1343 is the last character in the expansion of S2 and n is the difference
1344 between the two lengths.
1345 Upon successful completion, S2->length is set to S1->length. The only
1346 way this function can fail to make S2 as long as S1 is when S2 has
1347 zero-length, since in that case, there is no last character to repeat.
1348 So S2->length is required to be at least 1.
1350 Providing this functionality allows the user to do some pretty
1351 non-BSD (and non-portable) things: For example, the command
1352 tr -cs '[:upper:]0-9' '[:lower:]'
1353 is almost guaranteed to give results that depend on your collating
1357 string2_extend (s1, s2)
1358 const struct Spec_list *s1;
1359 struct Spec_list *s2;
1361 struct List_element *p;
1365 assert (translating);
1366 assert (s1->length > s2->length);
1367 assert (s2->length > 0);
1372 case RE_NORMAL_CHAR:
1373 char_to_repeat = p->u.normal_char;
1376 char_to_repeat = p->u.range.last_char;
1379 for (i = N_CHARS; i >= 0; i--)
1380 if (is_char_class_member (p->u.char_class, i))
1383 char_to_repeat = CHR (i);
1386 case RE_REPEATED_CHAR:
1387 char_to_repeat = p->u.repeated_char.the_repeated_char;
1390 case RE_EQUIV_CLASS:
1391 /* This shouldn't happen, because validate exits with an error
1392 if it finds an equiv class in string2 when translating. */
1405 append_repeated_char (s2, char_to_repeat, s1->length - s2->length);
1406 s2->length = s1->length;
1410 /* Die with an error message if S1 and S2 describe strings that
1411 are not valid with the given command line switches.
1412 A side effect of this function is that if a valid [c*] or
1413 [c*0] construct appears in string2, it is converted to [c*n]
1414 with a value for n that makes s2->length == s1->length. By
1415 the same token, if the --truncate-set1 option is not
1416 given, S2 may be extended. */
1420 const struct Spec_list *s1;
1421 struct Spec_list *s2;
1423 get_spec_stats (s1, -1);
1424 if (s1->n_indefinite_repeats > 0)
1426 error (1, 0, "the [c*] repeat construct may not appear in string1");
1429 /* FIXME: it isn't clear from the POSIX spec that this is invalid,
1430 but in the spirit of the other restrictions put on translation
1431 with character classes, this seems a logical interpretation. */
1432 if (complement && s1->has_upper_or_lower)
1435 "character classes may not be used when translating \
1436 and complementing");
1441 get_spec_stats (s2, s1->length);
1442 if (s2->has_restricted_char_class)
1445 "when translating, the only character classes that may \
1446 appear in\n\tstring2 are `upper' and `lower'");
1449 if (s2->n_indefinite_repeats > 1)
1451 error (1, 0, "only one [c*] repeat construct may appear in string2");
1456 if (s2->has_equiv_class)
1459 "[=c=] expressions may not appear in string2 \
1463 if (s1->length > s2->length)
1467 /* string2 must be non-empty unless --truncate-set1 is
1468 given or string1 is empty. */
1470 if (s2->length == 0)
1472 "when not truncating set1, string2 must be non-empty");
1473 string2_extend (s1, s2);
1477 if (complement && s2->has_upper_or_lower)
1479 "character classes may not be used when translating \
1480 and complementing");
1483 /* Not translating. */
1485 if (s2->n_indefinite_repeats > 0)
1487 "the [c*] construct may appear in string2 only \
1493 /* Read buffers of SIZE bytes via the function READER (if READER is
1494 NULL, read from stdin) until EOF. When non-NULL, READER is either
1495 read_and_delete or read_and_xlate. After each buffer is read, it is
1496 processed and written to stdout. The buffers are processed so that
1497 multiple consecutive occurrences of the same character in the input
1498 stream are replaced by a single occurrence of that character if the
1499 character is in the squeeze set. */
1502 squeeze_filter (buf, size, reader)
1507 unsigned int char_to_squeeze = NOT_A_CHAR;
1518 nr = safe_read (0, (char *) buf, size);
1520 nr = (*reader) (buf, size, NULL);
1523 error (1, errno, "read error");
1531 if (char_to_squeeze == NOT_A_CHAR)
1534 /* Here, by being a little tricky, we can get a significant
1535 performance increase in most cases when the input is
1536 reasonably large. Since tr will modify the input only
1537 if two consecutive (and identical) input characters are
1538 in the squeeze set, we can step by two through the data
1539 when searching for a character in the squeeze set. This
1540 means there may be a little more work in a few cases and
1541 perhaps twice as much work in the worst cases where most
1542 of the input is removed by squeezing repeats. But most
1543 uses of this functionality seem to remove less than 20-30%
1545 for (; i < nr && !in_squeeze_set[buf[i]]; i += 2)
1548 /* There is a special case when i == nr and we've just
1549 skipped a character (the last one in buf) that is in
1551 if (i == nr && in_squeeze_set[buf[i - 1]])
1555 out_len = nr - begin;
1558 char_to_squeeze = buf[i];
1559 /* We're about to output buf[begin..i]. */
1560 out_len = i - begin + 1;
1562 /* But since we stepped by 2 in the loop above,
1563 out_len may be one too large. */
1564 if (i > 0 && buf[i - 1] == char_to_squeeze)
1567 /* Advance i to the index of first character to be
1568 considered when looking for a char different from
1573 && fwrite ((char *) &buf[begin], 1, out_len, stdout) == 0)
1574 error (1, errno, "write error");
1577 if (char_to_squeeze != NOT_A_CHAR)
1579 /* Advance i to index of first char != char_to_squeeze
1580 (or to nr if all the rest of the characters in this
1581 buffer are the same as char_to_squeeze). */
1582 for (; i < nr && buf[i] == char_to_squeeze; i++)
1585 char_to_squeeze = NOT_A_CHAR;
1586 /* If (i >= nr) we've squeezed the last character in this buffer.
1587 So now we have to read a new buffer and continue comparing
1588 characters against char_to_squeeze. */
1593 /* Read buffers of SIZE bytes from stdin until one is found that
1594 contains at least one character not in the delete set. Store
1595 in the array BUF, all characters from that buffer that are not
1596 in the delete set, and return the number of characters saved
1600 read_and_delete (buf, size, not_used)
1606 static int hit_eof = 0;
1608 assert (not_used == NULL);
1614 /* This enclosing do-while loop is to make sure that
1615 we don't return zero (indicating EOF) when we've
1616 just deleted all the characters in a buffer. */
1620 int nr = safe_read (0, (char *) buf, size);
1623 error (1, errno, "read error");
1630 /* This first loop may be a waste of code, but gives much
1631 better performance when no characters are deleted in
1632 the beginning of a buffer. It just avoids the copying
1633 of buf[i] into buf[n_saved] when it would be a NOP. */
1635 for (i = 0; i < nr && !in_delete_set[buf[i]]; i++)
1639 for (++i; i < nr; i++)
1640 if (!in_delete_set[buf[i]])
1641 buf[n_saved++] = buf[i];
1643 while (n_saved == 0);
1648 /* Read at most SIZE bytes from stdin into the array BUF. Then
1649 perform the in-place and one-to-one mapping specified by the global
1650 array `xlate'. Return the number of characters read, or 0 upon EOF. */
1653 read_and_xlate (buf, size, not_used)
1658 long chars_read = 0;
1659 static int hit_eof = 0;
1662 assert (not_used == NULL);
1668 chars_read = safe_read (0, (char *) buf, size);
1670 error (1, errno, "read error");
1671 if (chars_read == 0)
1677 for (i = 0; i < chars_read; i++)
1678 buf[i] = xlate[buf[i]];
1683 /* Initialize a boolean membership set IN_SET with the character
1684 values obtained by traversing the linked list of constructs S
1685 using the function `get_next'. If COMPLEMENT_THIS_SET is
1686 non-zero the resulting set is complemented. */
1689 set_initialize (s, complement_this_set, in_set)
1690 struct Spec_list *s;
1691 int complement_this_set;
1697 memset (in_set, 0, N_CHARS * sizeof (in_set[0]));
1698 s->state = BEGIN_STATE;
1699 while ((c = get_next (s, NULL)) != -1)
1701 if (complement_this_set)
1702 for (i = 0; i < N_CHARS; i++)
1703 in_set[i] = (!in_set[i]);
1712 int non_option_args;
1713 struct Spec_list buf1, buf2;
1714 struct Spec_list *s1 = &buf1;
1715 struct Spec_list *s2 = &buf2;
1717 program_name = argv[0];
1719 while ((c = getopt_long (argc, argv, "cdst", long_options,
1736 squeeze_repeats = 1;
1751 printf ("tr - %s\n", version_string);
1758 posix_pedantic = (getenv ("POSIXLY_CORRECT") != NULL);
1760 non_option_args = argc - optind;
1761 translating = (non_option_args == 2 && !delete);
1763 /* Change this test if it is valid to give tr no options and
1764 no args at all. POSIX doesn't specifically say anything
1765 either way, but it looks like they implied it's invalid
1766 by omission. If you want to make tr do a slow imitation
1767 of `cat' use `tr a a'. */
1768 if (non_option_args > 2)
1770 error (0, 0, "too many arguments");
1774 if (!delete && !squeeze_repeats && non_option_args != 2)
1775 error (1, 0, "two strings must be given when translating");
1777 if (delete && squeeze_repeats && non_option_args != 2)
1778 error (1, 0, "two strings must be given when both \
1779 deleting and squeezing repeats");
1781 /* If --delete is given without --squeeze-repeats, then
1782 only one string argument may be specified. But POSIX
1783 says to ignore any string2 in this case, so if POSIXLY_CORRECT
1784 is set, pretend we never saw string2. But I think
1785 this deserves a fatal error, so that's the default. */
1786 if ((delete && !squeeze_repeats) && non_option_args != 1)
1788 if (posix_pedantic && non_option_args == 2)
1792 "only one string may be given when deleting \
1793 without squeezing repeats");
1796 if (squeeze_repeats && non_option_args == 0)
1797 error (1, 0, "at least one string must be given when squeezing repeats");
1800 if (parse_str ((unsigned char *) argv[optind], s1))
1803 if (non_option_args == 2)
1806 if (parse_str ((unsigned char *) argv[optind + 1], s2))
1814 if (squeeze_repeats && non_option_args == 1)
1816 set_initialize (s1, complement, in_squeeze_set);
1817 squeeze_filter (io_buf, IO_BUF_SIZE, NULL);
1819 else if (delete && non_option_args == 1)
1823 set_initialize (s1, complement, in_delete_set);
1826 nr = read_and_delete (io_buf, IO_BUF_SIZE, NULL);
1827 if (nr > 0 && fwrite ((char *) io_buf, 1, nr, stdout) == 0)
1828 error (1, errno, "write error");
1832 else if (squeeze_repeats && delete && non_option_args == 2)
1834 set_initialize (s1, complement, in_delete_set);
1835 set_initialize (s2, 0, in_squeeze_set);
1836 squeeze_filter (io_buf, IO_BUF_SIZE, (PFI) read_and_delete);
1838 else if (translating)
1843 SET_TYPE *in_s1 = in_delete_set;
1845 set_initialize (s1, 0, in_s1);
1846 s2->state = BEGIN_STATE;
1847 for (i = 0; i < N_CHARS; i++)
1849 for (i = 0; i < N_CHARS; i++)
1853 int ch = get_next (s2, NULL);
1854 assert (ch != -1 || truncate_set1);
1857 /* This will happen when tr is invoked like e.g.
1858 tr -cs A-Za-z0-9 '\012'. */
1864 assert (get_next (s2, NULL) == -1 || truncate_set1);
1870 enum Upper_Lower_class class_s1;
1871 enum Upper_Lower_class class_s2;
1873 for (i = 0; i < N_CHARS; i++)
1875 s1->state = BEGIN_STATE;
1876 s2->state = BEGIN_STATE;
1879 c1 = get_next (s1, &class_s1);
1880 c2 = get_next (s2, &class_s2);
1881 if (!class_ok[(int) class_s1][(int) class_s2])
1883 "misaligned or mismatched upper and/or lower classes");
1884 /* The following should have been checked by validate... */
1889 assert (c1 == -1 || truncate_set1);
1891 if (squeeze_repeats)
1893 set_initialize (s2, 0, in_squeeze_set);
1894 squeeze_filter (io_buf, IO_BUF_SIZE, (PFI) read_and_xlate);
1902 chars_read = read_and_xlate (io_buf, IO_BUF_SIZE, NULL);
1904 && fwrite ((char *) io_buf, 1, chars_read, stdout) == 0)
1905 error (1, errno, "write error");
1907 while (chars_read > 0);
1911 if (fclose (stdout) == EOF)
1912 error (2, errno, "write error");
1915 error (2, errno, "standard input");