bees@infoswx.UUCP (11/25/85)
The following source for grep compiles and runs on the Amiga.
Pass 1 came up with a few warnings, but no errors. I made no
modifications to the original which is supposed to run on the
IBM-PC. I also have not done extensive testing. I compiled
on my development system with:
execute make grep
I ran:
grep grep grep.c
with success, and also ran:
grep ?
which prints out more than a screenful of help.
Have fun!
Ray Davis
---------------- cut wherever you like, but here might be best --------------
/*
*
*
* The information in this document is subject to change
* without notice and should not be construed as a commitment
* by Digital Equipment Corporation or by DECUS.
*
* Neither Digital Equipment Corporation, DECUS, nor the authors
* assume any responsibility for the use or reliability of this
* document or the described software.
*
* Copyright (C) 1980, DECUS
*
*
* General permission to copy or modify, but not for profit, is
* hereby granted, provided that the above copyright notice is
* included and reference made to the fact that reproduction
* privileges were granted by DECUS.
*
*/
#include <stdio.h>
#include <ctype.h>
/*
* grep.
*
* Runs on the Decus compiler or on vms.
* Converted for BDS compiler (under CP/M-80), 20-Jan-83, by Chris Kern.
*
* Converted to IBM PC with CI-C86 C Compiler June 1983 by David N. Smith
*
* On vms, define as:
*
* grep :== "$disk:[account]grep" (native)
* grep :== "$disk:[account]grep grep" (Decus)
*
* See below for more information.
*
*/
char *documentation[] = {
"grep searches a file for a given pattern. Execute by",
" grep [flags] regular_expression file_list",
"",
"Flags are single characters preceeded by '-':",
" -c Only a count of matching lines is printed",
" -f Print file name for matching lines switch, see below",
" -n Each line is preceeded by its line number",
" -v Only print non-matching lines",
"",
"The file_list is a list of files (wildcards are acceptable on RSX modes).",
"",
"The file name is normally printed if there is a file given.",
"The -f flag reverses this action (print name no file, not if more).",
"",
0 };
char *patdoc[] = {
"The regular_expression defines the pattern to search for. Upper- and",
"lower-case are always ignored. Blank lines never match. The expression",
"should be quoted to prevent file-name translation.",
"x An ordinary character (not mentioned below) matches that character.",
"'\\' The backslash quotes any character. \"\\$\" matches a dollar-sign.",
"'^' A circumflex at the beginning of an expression matches the",
" beginning of a line.",
"'$' A dollar-sign at the end of an expression matches the end of a line.",
"'.' A period matches any character except \"new-line\".",
"':a' A colon matches a class of characters described by the following",
"':d' character. \":a\" matches any alphabetic, \":d\" matches digits,",
"':n' \":n\" matches alphanumerics, \": \" matches spaces, tabs, and",
"': ' other control characters, such as new-line.",
"'*' An expression followed by an asterisk matches zero or more",
" occurrances of that expression: \"fo*\" matches \"f\", \"fo\"",
" \"foo\", etc.",
"'+' An expression followed by a plus sign matches one or more",
" occurrances of that expression: \"fo+\" matches \"fo\", etc.",
"'-' An expression followed by a minus sign optionally matches",
" the expression.",
"'[]' A string enclosed in square brackets matches any character in",
" that string, but no others. If the first character in the",
" string is a circumflex, the expression matches any character",
" except \"new-line\" and the characters in the string. For",
" example, \"[xyz]\" matches \"xx\" and \"zyx\", while \"[^xyz]\"",
" matches \"abc\" but not \"axb\". A range of characters may be",
" specified by two characters separated by \"-\". Note that,",
" [a-z] matches alphabetics, while [z-a] never matches.",
"The concatenation of regular expressions is a regular expression.",
0};
/*$ifdef vms */
/*$define VMS VMS native compiler */
/*$define error(s) _error(s) */
/*$endif */
#define LMAX 512
#define PMAX 256
#define CHAR 1
#define BOL 2
#define EOL 3
#define ANY 4
#define CLASS 5
#define NCLASS 6
#define STAR 7
#define PLUS 8
#define MINUS 9
#define ALPHA 10
#define DIGIT 11
#define NALPHA 12
#define PUNCT 13
#define RANGE 14
#define ENDPAT 15
int cflag;
int fflag;
int nflag;
int vflag;
int nfile;
int debug = 0; /* Set for debug code */
char *pp;
#ifndef vms
char file_name[81];
#endif
char lbuf[LMAX];
char pbuf[PMAX];
/*******************************************************/
main(argc, argv)
char *argv[];
{
register char *p;
register int c, i;
int gotpattern;
int gotcha;
FILE *f;
if (argc <= 1)
usage("No arguments");
if (argc == 2 && argv[1][0] == '?' && argv[1][1] == 0) {
help(documentation);
help(patdoc);
return;
}
nfile = argc-1;
gotpattern = 0;
for (i=1; i < argc; ++i) {
p = argv[i];
if (*p == '-') {
++p;
while (c = *p++) {
switch(tolower(c)) {
case '?':
help(documentation);
break;
case 'C':
case 'c':
++cflag;
break;
case 'D':
case 'd':
++debug;
break;
case 'F':
case 'f':
++fflag;
break;
case 'n':
case 'N':
++nflag;
break;
case 'v':
case 'V':
++vflag;
break;
default:
usage("Unknown flag");
}
}
argv[i] = 0;
--nfile;
} else if (!gotpattern) {
compile(p);
argv[i] = 0;
++gotpattern;
--nfile;
}
}
if (!gotpattern)
usage("No pattern");
if (nfile == 0)
grep(stdin, 0);
else {
fflag = fflag ^ (nfile > 0);
for (i=1; i < argc; ++i) {
if (p = argv[i]) {
if ((f=fopen(p, "r")) == NULL)
cant(p);
else {
grep(f, p);
fclose(f);
}
}
}
}
}
/*******************************************************/
file(s)
char *s;
{
printf("File %s:\n", s);
}
/*******************************************************/
cant(s)
char *s;
{
fprintf(stderr, "%s: cannot open\n", s);
}
/*******************************************************/
help(hp)
char *hp;
/*
* Give good help
*/
{
register char **dp;
for (dp = hp; *dp; dp++)
printf("%s\n", *dp);
}
/*******************************************************/
usage(s)
char *s;
{
fprintf(stderr, "?GREP-E-%s\n", s);
fprintf(stderr,
"Usage: grep [-cfnv] pattern [file ...]. grep ? for help\n");
exit(1);
}
/*******************************************************/
compile(source)
char *source; /* Pattern to compile */
/*
* Compile the pattern into global pbuf[]
*/
{
register char *s; /* Source string pointer */
register char *lp; /* Last pattern pointer */
register int c; /* Current character */
int o; /* Temp */
char *spp; /* Save beginning of pattern */
char *cclass(); /* Compile class routine */
s = source;
if (debug)
printf("Pattern = \"%s\"\n", s);
pp = pbuf;
while (c = *s++) {
/*
* STAR, PLUS and MINUS are special.
*/
if (c == '*' || c == '+' || c == '-') {
if (pp == pbuf ||
(o=pp[-1]) == BOL ||
o == EOL ||
o == STAR ||
o == PLUS ||
o == MINUS)
badpat("Illegal occurrance op.", source, s);
store(ENDPAT);
store(ENDPAT);
spp = pp; /* Save pattern end */
while (--pp > lp) /* Move pattern down */
*pp = pp[-1]; /* one byte */
*pp = (c == '*') ? STAR :
(c == '-') ? MINUS : PLUS;
pp = spp; /* Restore pattern end */
continue;
}
/*
* All the rest.
*/
lp = pp; /* Remember start */
switch(c) {
case '^':
store(BOL);
break;
case '$':
store(EOL);
break;
case '.':
store(ANY);
break;
case '[':
s = cclass(source, s);
break;
case ':':
if (*s) {
c = *s++;
switch(tolower(c)) {
case 'a':
case 'A':
store(ALPHA);
break;
case 'd':
case 'D':
store(DIGIT);
break;
case 'n':
case 'N':
store(NALPHA);
break;
case ' ':
store(PUNCT);
break;
default:
badpat("Unknown : type", source, s);
}
break;
}
else badpat("No : type", source, s);
case '\\':
if (*s)
c = *s++;
default:
store(CHAR);
store(tolower(c));
}
}
store(ENDPAT);
store(0); /* Terminate string */
if (debug) {
for (lp = pbuf; lp < pp;) {
if ((c = (*lp++ & 0377)) < ' ')
printf("\\%o ", c);
else printf("%c ", c);
}
printf("\n");
}
}
/*******************************************************/
char *
cclass(source, src)
char *source; /* Pattern start -- for error msg. */
char *src; /* Class start */
/*
* Compile a class (within [])
*/
{
register char *s; /* Source pointer */
register char *cp; /* Pattern start */
register int c; /* Current character */
int o; /* Temp */
s = src;
o = CLASS;
if (*s == '^') {
++s;
o = NCLASS;
}
store(o);
cp = pp;
store(0); /* Byte count */
while ((c = *s++) && c!=']') {
if (c == '\\') { /* Store quoted char */
if ((c = *s++) == '\0') /* Gotta get something */
badpat("Class terminates badly", source, s);
else store(tolower(c));
}
else if (c == '-' &&
(pp - cp) > 1 && *s != ']' && *s != '\0') {
c = pp[-1]; /* Range start */
pp[-1] = RANGE; /* Range signal */
store(c); /* Re-store start */
c = *s++; /* Get end char and*/
store(tolower(c)); /* Store it */
}
else {
store(tolower(c)); /* Store normal char */
}
}
if (c != ']')
badpat("Unterminated class", source, s);
if ((c = (pp - cp)) >= 256)
badpat("Class too large", source, s);
if (c == 0)
badpat("Empty class", source, s);
*cp = c;
return(s);
}
/*******************************************************/
store(op)
{
if (pp >= &pbuf[PMAX])
error("Pattern too complex\n");
*pp++ = op;
}
/*******************************************************/
badpat(message, source, stop)
char *message; /* Error message */
char *source; /* Pattern start */
char *stop; /* Pattern end */
{
register int c;
fprintf(stderr, "-GREP-E-%s, pattern is\"%s\"\n", message, source);
fprintf(stderr, "-GREP-E-Stopped at byte %d, '%c'\n",
stop-source, stop[-1]);
error("?GREP-E-Bad pattern\n");
}
/*******************************************************/
grep(fp, fn)
FILE *fp; /* File to process */
char *fn; /* File name (for -f option) */
/*
* Scan the file for the pattern in pbuf[]
*/
{
register int lno, count, m;
lno = 0;
count = 0;
while (fgets(lbuf, LMAX, fp)) {
++lno;
m = match();
if ((m && !vflag) || (!m && vflag)) {
++count;
if (!cflag) {
if (fflag && fn) {
file(fn);
fn = 0;
}
if (nflag)
printf("%d\t", lno);
printf("%s\n", lbuf);
}
}
}
if (cflag) {
if (fflag && fn)
file(fn);
printf("%d\n", count);
}
}
/*******************************************************/
match()
/*
* Match the current line (in lbuf[]), return 1 if it does.
*/
{
register char *l; /* Line pointer */
char *pmatch();
for (l = lbuf; *l; l++) {
if (pmatch(l, pbuf))
return(1);
}
return(0);
}
/*******************************************************/
char *
pmatch(line, pattern)
char *line; /* (partial) line to match */
char *pattern; /* (partial) pattern to match */
{
register char *l; /* Current line pointer */
register char *p; /* Current pattern pointer */
register char c; /* Current character */
char *e; /* End for STAR and PLUS match */
int op; /* Pattern operation */
int n; /* Class counter */
char *are; /* Start of STAR match */
l = line;
if (debug > 1)
printf("pmatch(\"%s\")\n", line);
p = pattern;
while ((op = *p++) != ENDPAT) {
if (debug > 1)
printf("byte[%d] = 0%o, '%c', op = 0%o\n",
l-line, *l, *l, op);
switch(op) {
case CHAR:
if (tolower(*l) != *p++)
return(0);
l++;
break;
case BOL:
if (l != lbuf)
return(0);
break;
case EOL:
if (*l != '\0')
return(0);
break;
case ANY:
if (*l++ == '\0')
return(0);
break;
case DIGIT:
if ((c = *l++) < '0' || (c > '9'))
return(0);
break;
case ALPHA:
c = tolower(*l);
l++;
if (c < 'a' || c > 'z')
return(0);
break;
case NALPHA:
c = tolower(*l);
l++;
if (c >= 'a' && c <= 'z')
break;
else if (c < '0' || c > '9')
return(0);
break;
case PUNCT:
c = *l++;
if (c == 0 || c > ' ')
return(0);
break;
case CLASS:
case NCLASS:
c = tolower(*l);
l++;
n = *p++ & 0377;
do {
if (*p == RANGE) {
p += 3;
n -= 2;
if (c >= p[-2] && c <= p[-1])
break;
}
else if (c == *p++)
break;
} while (--n > 1);
if ((op == CLASS) == (n <= 1))
return(0);
if (op == CLASS)
p += n - 2;
break;
case MINUS:
e = pmatch(l, p); /* Look for a match */
while (*p++ != ENDPAT); /* Skip over pattern */
if (e) /* Got a match? */
l = e; /* Yes, update string */
break; /* Always succeeds */
case PLUS: /* One or more ... */
if ((l = pmatch(l, p)) == 0)
return(0); /* Gotta have a match */
case STAR: /* Zero or more ... */
are = l; /* Remember line start */
while (*l && (e = pmatch(l, p)))
l = e; /* Get longest match */
while (*p++ != ENDPAT); /* Skip over pattern */
while (l >= are) { /* Try to match rest */
if (e = pmatch(l, p))
return(e);
--l; /* Nope, try earlier */
}
return(0); /* Nothing else worked */
default:
printf("Bad op code %d\n", op);
error("Cannot happen -- match\n");
}
}
return(l);
}
/*******************************************************/
error(s)
char *s;
{
fprintf(stderr, "%s", s);
exit(1);
}