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
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
|
#include "../command.h"
#include <stdio.h>
static struct {
bool filename_prefix;
bool never_file_prefix;
bool line_number;
bool only_matching_names;
bool only_non_matching_names;
bool only_line_count;
bool only_matching_part;
bool quiet;
bool inverse;
bool ignore_case;
bool is_regex;
} flags;
static int short_arg(char c, char* next) {
UNUSED(next);
switch (c) {
case 'H':
flags.filename_prefix = true;
break;
case 'h':
flags.never_file_prefix = true;
break;
case 'n':
flags.line_number = true;
break;
case 'l':
flags.only_matching_names = true;
break;
case 'L':
flags.only_non_matching_names = true;
break;
case 'c':
flags.only_line_count = true;
break;
case 'o':
flags.only_matching_part = true;
break;
case 'q':
flags.quiet = true;
break;
case 'v':
flags.inverse = true;
break;
case 'i':
flags.ignore_case = true;
break;
case 'F':
flags.is_regex = false;
break;
case 'E':
flags.is_regex = true;
break;
default:
return ARG_INVALID;
}
return ARG_UNUSED;
}
static void help(void) {
printf("Usage: grep [-HhlLoqviFE] [-m N] PATTERN [FILE]...\n");
printf("Search for PATTERN in FILEs (or stdin)\n");
printf("\t-H\tAdd 'filename:' prefix\n");
printf("\t-h\tDo not add 'filename:' prefix\n");
printf("\t-n\tAdd 'line_no:' prefix\n");
printf("\t-l\tShow only names of files that match\n");
printf("\t-L\tShow only names of files that don't match\n");
printf("\t-c\tShow only count of matching lines\n");
printf("\t-o\tShow only the matching part of line\n");
printf("\t-q\tQuiet. Return 0 if PATTERN is found, 1 otherwise\n");
printf("\t-v\tSelect non-matching lines\n");
printf("\t-i\tIgnore case\n");
printf("\t-F\tPATTERN is a literal (not regexp)\n");
printf("\t-E\tPATTERN is an extended regexp\n");
}
static bool match_regex(char** string, re_t pattern) {
int len;
int index;
if ((index = re_matchp(pattern, *string, &len)) < 0) return false;
if (flags.only_matching_part) {
(*string) += index;
(*string)[len] = '\0';
}
return true;
}
static bool match_literal(char** string, char* pattern) {
char* match = *string;
size_t match_len = strlen(match);
size_t pattern_len = strlen(pattern);
if (match_len < pattern_len) return false;
for (size_t i = 0; i < match_len - pattern_len + 1; i++) {
if (
(!flags.ignore_case && strncmp(match + i, pattern, pattern_len) == 0) ||
(flags.ignore_case && strncasecmp(match + i, pattern, pattern_len) == 0)
) {
if (flags.only_matching_part) {
*string = (*string) + i;
(*string)[pattern_len] = '\0';
}
return true;
}
}
return false;
}
static bool match(char** string, void* pattern) {
bool result;
if (flags.is_regex) {
result = match_regex(string, (re_t) pattern);
} else {
result = match_literal(string, (char*) pattern);
}
return (flags.inverse ? !result : result);
}
static bool match_any(char* path, void* pattern) {
FILE* file = get_file_s(path, "r");
if (file == NULL) return false;
char* buf = NULL;
size_t offset;
bool matched = false;
int read;
while ((read = getline(&buf, &offset, file)) > 0) {
if (buf[read-1] == '\n') buf[read-1] = '\0';
char* save = buf;
if (match(&save, pattern)) {
matched = true;
break;
}
}
if (buf != NULL) free(buf);
return matched;
}
static bool match_file(char* path, void* pattern, bool many) {
FILE* file = get_file_s(path, "r");
if (file == NULL) return false;
int num_matched = 0;
int line_num = 0;
char* buf = NULL;
size_t offset;
int read;
while((read = getline(&buf, &offset, file)) > 0) {
if (buf[read-1] == '\n') buf[read-1] = '\0';
char* matched = buf;
line_num++;
if (!match(&matched, pattern)) {
continue;
}
num_matched++;
if (flags.only_line_count || flags.quiet) continue;
if ((many || flags.filename_prefix) && !flags.never_file_prefix) {
print_file_path(path);
putchar(':');
}
if (flags.line_number) {
printf("%d:", line_num);
}
if (flags.only_matching_part) {
printf("%s\n", matched);
} else {
printf("%s\n", buf);
}
}
if (!flags.quiet && flags.only_line_count) {
if ((many || flags.filename_prefix) && !flags.never_file_prefix) {
print_file_path(path);
putchar(':');
}
printf("%d\n", num_matched);
}
if (buf != NULL) free(buf);
return num_matched != 0;
}
static void* compile(char* pattern) {
if (flags.is_regex) {
return re_compile(pattern);
} else {
return pattern;
}
}
static bool run_match(char* path, void* pattern, bool many) {
bool result;
if (flags.only_matching_names || flags.only_non_matching_names) {
result = match_any(path, pattern);
if (flags.only_non_matching_names) result = !result;
if (result && !flags.quiet) {
print_file_path(path);
putchar('\n');
}
return result;
} else {
return match_file(path, pattern, many);
}
}
COMMAND(grep) {
flags.only_matching_part = false;
flags.only_non_matching_names = false;
flags.only_matching_names = false;
flags.only_line_count = false;
flags.quiet = false;
flags.is_regex = true;
flags.line_number = false;
flags.never_file_prefix = false;
flags.filename_prefix = false;
flags.inverse = false;
int start = parse_args(argc, argv, help, short_arg, NULL);
if (argc - start < 1) global_help(help);
char* pattern = argv[start++];
bool many = argc - start > 0;
bool ok = false;
void* compiled = compile(pattern);
if (run_match("-", compiled, many)) ok = true;
for (int i = start; i < argc; i++) {
if (run_match(argv[i], compiled, many)) ok = true;
}
if (flags.quiet) {
return ok ? EXIT_SUCCESS : EXIT_FAILURE;
} else {
return EXIT_SUCCESS;
}
}
|
