2 * The information in this document is subject to change
3 * without notice and should not be construed as a commitment
4 * by Digital Equipment Corporation or by DECUS.
6 * Neither Digital Equipment Corporation, DECUS, nor the authors
7 * assume any responsibility for the use or reliability of this
8 * document or the described software.
10 * Copyright (C) 1980, DECUS
12 * General permission to copy or modify, but not for profit, is
13 * hereby granted, provided that the above copyright notice is
14 * included and reference made to the fact that reproduction
15 * privileges were granted by DECUS.
19 #include <ctype.h> // tolower()
24 * Runs on the Decus compiler or on vms, On vms, define as:
25 * grep :== "$disk:[account]grep" (native)
26 * grep :== "$disk:[account]grep grep" (Decus)
27 * See below for more information.
30 char *documentation
[] = {
31 "grep searches a file for a given pattern. Execute by",
32 " grep [flags] regular_expression file_list\n",
33 "Flags are single characters preceded by '-':",
34 " -c Only a count of matching lines is printed",
35 " -f Print file name for matching lines switch, see below",
36 " -n Each line is preceded by its line number",
37 " -v Only print non-matching lines\n",
38 "The file_list is a list of files (wildcards are acceptable on RSX modes).",
39 "\nThe file name is normally printed if there is a file given.",
40 "The -f flag reverses this action (print name no file, not if more).\n",
44 "The regular_expression defines the pattern to search for. Upper- and",
45 "lower-case are always ignored. Blank lines never match. The expression",
46 "should be quoted to prevent file-name translation.",
47 "x An ordinary character (not mentioned below) matches that character.",
48 "'\\' The backslash quotes any character. \"\\$\" matches a dollar-sign.",
49 "'^' A circumflex at the beginning of an expression matches the",
50 " beginning of a line.",
51 "'$' A dollar-sign at the end of an expression matches the end of a line.",
52 "'.' A period matches any character except \"new-line\".",
53 "':a' A colon matches a class of characters described by the following",
54 "':d' character. \":a\" matches any alphabetic, \":d\" matches digits,",
55 "':n' \":n\" matches alphanumerics, \": \" matches spaces, tabs, and",
56 "': ' other control characters, such as new-line.",
57 "'*' An expression followed by an asterisk matches zero or more",
58 " occurrences of that expression: \"fo*\" matches \"f\", \"fo\"",
60 "'+' An expression followed by a plus sign matches one or more",
61 " occurrences of that expression: \"fo+\" matches \"fo\", etc.",
62 "'-' An expression followed by a minus sign optionally matches",
64 "'[]' A string enclosed in square brackets matches any character in",
65 " that string, but no others. If the first character in the",
66 " string is a circumflex, the expression matches any character",
67 " except \"new-line\" and the characters in the string. For",
68 " example, \"[xyz]\" matches \"xx\" and \"zyx\", while \"[^xyz]\"",
69 " matches \"abc\" but not \"axb\". A range of characters may be",
70 " specified by two characters separated by \"-\". Note that,",
71 " [a-z] matches alphabetics, while [z-a] never matches.",
72 "The concatenation of regular expressions is a regular expression.",
94 int cflag
=0, fflag
=0, nflag
=0, vflag
=0, nfile
=0, debug
=0;
96 char *pp
, lbuf
[LMAX
], pbuf
[PMAX
];
102 void badpat(char *, char *, char *);
106 /*** Display a file name *******************************/
109 printf("File %s:\n", s
);
112 /*** Report unopenable file ****************************/
115 fprintf(stderr
, "%s: cannot open\n", s
);
118 /*** Give good help ************************************/
123 for (dp
= hp
; *dp
; ++dp
)
127 /*** Display usage summary *****************************/
130 fprintf(stderr
, "?GREP-E-%s\n", s
);
132 "Usage: grep [-cfnv] pattern [file ...]. grep ? for help\n");
136 /*** Compile the pattern into global pbuf[] ************/
137 void compile(char *source
)
139 char *s
; /* Source string pointer */
140 char *lp
; /* Last pattern pointer */
141 int c
; /* Current character */
143 char *spp
; /* Save beginning of pattern */
147 printf("Pattern = \"%s\"\n", s
);
151 * STAR, PLUS and MINUS are special.
153 if (c
== '*' || c
== '+' || c
== '-') {
160 badpat("Illegal occurrence op.", source
, s
);
163 spp
= pp
; /* Save pattern end */
164 while (--pp
> lp
) /* Move pattern down */
165 *pp
= pp
[-1]; /* one byte */
166 *pp
= (c
== '*') ? STAR
:
167 (c
== '-') ? MINUS
: PLUS
;
168 pp
= spp
; /* Restore pattern end */
174 lp
= pp
; /* Remember start */
190 s
= cclass(source
, s
);
195 switch(tolower(c
= *s
++)) {
217 badpat("Unknown : type", source
, s
);
222 else badpat("No : type", source
, s
);
234 store(0); /* Terminate string */
236 for (lp
= pbuf
; lp
< pp
;) {
237 if ((c
= (*lp
++ & 0377)) < ' ')
239 else printf("%c ", c
);
245 /*** Compile a class (within []) ***********************/
246 char *cclass(char *source
, char *src
)
247 /* char *source; // Pattern start -- for error msg. */
248 /* char *src; // Class start */
250 char *s
; /* Source pointer */
251 char *cp
; /* Pattern start */
252 int c
; /* Current character */
263 store(0); /* Byte count */
264 while ((c
= *s
++) && c
!=']') {
265 if (c
== '\\') { /* Store quoted char */
266 if ((c
= *s
++) == '\0') /* Gotta get something */
267 badpat("Class terminates badly", source
, s
);
268 else store(tolower(c
));
271 (pp
- cp
) > 1 && *s
!= ']' && *s
!= '\0') {
272 c
= pp
[-1]; /* Range start */
273 pp
[-1] = RANGE
; /* Range signal */
274 store(c
); /* Re-store start */
275 c
= *s
++; /* Get end char and*/
276 store(tolower(c
)); /* Store it */
279 store(tolower(c
)); /* Store normal char */
283 badpat("Unterminated class", source
, s
);
284 if ((c
= (pp
- cp
)) >= 256)
285 badpat("Class too large", source
, s
);
287 badpat("Empty class", source
, s
);
292 /*** Store an entry in the pattern buffer **************/
295 if (pp
>= &pbuf
[PMAX
])
296 error("Pattern too complex\n");
300 /*** Report a bad pattern specification ****************/
301 void badpat(char *message
, char *source
, char *stop
)
302 /* char *message; // Error message */
303 /* char *source; // Pattern start */
304 /* char *stop; // Pattern end */
306 fprintf(stderr
, "-GREP-E-%s, pattern is\"%s\"\n", message
, source
);
307 fprintf(stderr
, "-GREP-E-Stopped at byte %ld, '%c'\n",
308 stop
-source
, stop
[-1]);
309 error("?GREP-E-Bad pattern\n");
312 /*** Scan the file for the pattern in pbuf[] ***********/
313 void grep(FILE *fp
, char *fn
)
314 /* FILE *fp; // File to process */
315 /* char *fn; // File name (for -f option) */
321 while (fgets(lbuf
, LMAX
, fp
)) {
324 if ((m
&& !vflag
) || (!m
&& vflag
)) {
333 printf("%s\n", lbuf
);
340 printf("%d\n", count
);
344 /*** Match line (lbuf) with pattern (pbuf) return 1 if match ***/
347 char *l
; /* Line pointer */
349 for (l
= lbuf
; *l
; ++l
) {
356 /*** Match partial line with pattern *******************/
357 char *pmatch(char *line
, char *pattern
)
358 /* char *line; // (partial) line to match */
359 /* char *pattern; // (partial) pattern to match */
361 char *l
; /* Current line pointer */
362 char *p
; /* Current pattern pointer */
363 char c
; /* Current character */
364 char *e
; /* End for STAR and PLUS match */
365 int op
; /* Pattern operation */
366 int n
; /* Class counter */
367 char *are
; /* Start of STAR match */
371 printf("pmatch(\"%s\")\n", line
);
373 while ((op
= *p
++) != ENDPAT
) {
375 printf("byte[%ld] = 0%o, '%c', op = 0%o\n",
380 if (tolower(*l
++) != *p
++)
400 if ((c
= *l
++) < '0' || (c
> '9'))
406 if (c
< 'a' || c
> 'z')
412 if (c
>= 'a' && c
<= 'z')
414 else if (c
< '0' || c
> '9')
420 if (c
== 0 || c
> ' ')
432 if (c
>= p
[-2] && c
<= p
[-1])
438 if ((op
== CLASS
) == (n
<= 1))
445 e
= pmatch(l
, p
); /* Look for a match */
446 while (*p
++ != ENDPAT
); /* Skip over pattern */
447 if (e
) /* Got a match? */
448 l
= e
; /* Yes, update string */
449 break; /* Always succeeds */
451 case PLUS
: /* One or more ... */
452 if ((l
= pmatch(l
, p
)) == 0)
453 return(0); /* Gotta have a match */
454 case STAR
: /* Zero or more ... */
455 are
= l
; /* Remember line start */
456 while (*l
&& (e
= pmatch(l
, p
)))
457 l
= e
; /* Get longest match */
458 while (*p
++ != ENDPAT
); /* Skip over pattern */
459 while (l
> are
) { /* Try to match rest */
460 if (e
= pmatch(l
, p
))
462 --l
; /* Nope, try earlier */
464 if (e
= pmatch(l
, p
))
466 return(0); /* Nothing else worked */
469 printf("Bad op code %d\n", op
);
470 error("Cannot happen -- match\n");
476 /*** Report an error ***********************************/
479 fprintf(stderr
, "%s", s
);
483 /*** Main program - parse arguments & grep *************/
484 int main(int argc
, char **argv
)
493 usage("No arguments");
494 if (argc
== 2 && argv
[1][0] == '?' && argv
[1][1] == 0) {
501 for (i
=1; i
< argc
; ++i
) {
538 usage("Unknown flag");
543 } else if (!gotpattern
) {
555 fflag
= fflag
^ (nfile
> 0);
556 for (i
=1; i
< argc
; ++i
) {
558 if ((f
=fopen(p
, "r")) == NULL
)
570 /* vim: set expandtab ts=4 sw=3 sts=3 tw=80 :*/