summaryrefslogtreecommitdiff
path: root/findutils/grep.c
blob: a07feda03649c84e064320089b088a2b1cb9652c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
/*
 * 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 */