busybox/findutils/grep.c
1999-10-06 20:25:32 +00:00

211 lines
3.1 KiB
C

/*
* Copyright (c) 1999 by David I. Bell
* Permission is granted to use, distribute, or modify this source,
* provided that this copyright notice remains intact.
*
* The "grep" command, taken from sash.
* This provides basic file searching.
*
* Permission to distribute this code under the GPL has been granted.
* Modified for busybox by Erik Andersen <andersee@debian.org> <andersen@lineo.com>
*/
#include "internal.h"
#ifdef BB_GREP
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <ctype.h>
const char grep_usage[] =
"Search the input file(s) for lines matching the given pattern.\n"
"\tI search stdin if no files are given.\n"
"\tI can't grok full regular expressions.\n"
"usage: grep [in] PATTERN [FILES]...\n"
"\ti=ignore case, n=list line numbers\n";
static BOOL search
(const char * string, const char * word, BOOL ignoreCase);
extern int
grep_main(int argc, char ** argv)
{
FILE * fp;
const char * word;
const char * name;
const char * cp;
BOOL tellName;
BOOL ignoreCase;
BOOL tellLine;
long line;
char buf[BUF_SIZE];
ignoreCase = FALSE;
tellLine = FALSE;
argc--;
argv++;
if (argc < 1)
{
fprintf(stderr, "%s", grep_usage);
return 1;
}
if (**argv == '-')
{
argc--;
cp = *argv++;
while (*++cp) switch (*cp)
{
case 'i':
ignoreCase = TRUE;
break;
case 'n':
tellLine = TRUE;
break;
default:
fprintf(stderr, "Unknown option\n");
return 1;
}
}
word = *argv++;
argc--;
tellName = (argc > 1);
while (argc-- > 0)
{
name = *argv++;
fp = fopen(name, "r");
if (fp == NULL)
{
perror(name);
continue;
}
line = 0;
while (fgets(buf, sizeof(buf), fp))
{
line++;
cp = &buf[strlen(buf) - 1];
if (*cp != '\n')
fprintf(stderr, "%s: Line too long\n", name);
if (search(buf, word, ignoreCase))
{
if (tellName)
printf("%s: ", name);
if (tellLine)
printf("%ld: ", line);
fputs(buf, stdout);
}
}
if (ferror(fp))
perror(name);
fclose(fp);
}
return 0;
}
/*
* See if the specified word is found in the specified string.
*/
static BOOL
search(const char * string, const char * word, BOOL ignoreCase)
{
const char * cp1;
const char * cp2;
int len;
int lowFirst;
int ch1;
int ch2;
len = strlen(word);
if (!ignoreCase)
{
while (TRUE)
{
string = strchr(string, word[0]);
if (string == NULL)
return FALSE;
if (memcmp(string, word, len) == 0)
return TRUE;
string++;
}
}
/*
* Here if we need to check case independence.
* Do the search by lower casing both strings.
*/
lowFirst = *word;
if (isupper(lowFirst))
lowFirst = tolower(lowFirst);
while (TRUE)
{
while (*string && (*string != lowFirst) &&
(!isupper(*string) || (tolower(*string) != lowFirst)))
{
string++;
}
if (*string == '\0')
return FALSE;
cp1 = string;
cp2 = word;
do
{
if (*cp2 == '\0')
return TRUE;
ch1 = *cp1++;
if (isupper(ch1))
ch1 = tolower(ch1);
ch2 = *cp2++;
if (isupper(ch2))
ch2 = tolower(ch2);
}
while (ch1 == ch2);
string++;
}
}
#endif
/* END CODE */