1/* See LICENSE file for copyright and license details. */
2
3
4#include <stdio.h>
5#include <stdlib.h>
6#include <string.h>
7
8#include "text.h"
9#include "utf.h"
10#include "util.h"
11
12typedef struct Range {
13 size_t min, max;
14 struct Range *next;
15} Range;
16
17static Range *list = NULL;
18static char mode = 0;
19static char *delim = "\t";
20static size_t delimlen = 1;
21static int nflag = 0;
22static int sflag = 0;
23
24static void
25insert(Range *r)
26{
27 Range *l, *p, *t;
28
29 for (p = NULL, l = list; l; p = l, l = l->next) {
30 if (r->max && r->max + 1 < l->min) {
31 r->next = l;
32 break;
33 } else if (!l->max || r->min < l->max + 2) {
34 l->min = MIN(r->min, l->min);
35 for (p = l, t = l->next; t; p = t, t = t->next)
36 if (r->max && r->max + 1 < t->min)
37 break;
38 l->max = (p->max && r->max) ? MAX(p->max, r->max) : 0;
39 l->next = t;
40 return;
41 }
42 }
43 if (p)
44 p->next = r;
45 else
46 list = r;
47}
48
49static void
50parselist(char *str)
51{
52 char *s;
53 size_t n = 1;
54 Range *r;
55
56 if (!*str)
57 eprintf("empty list\n");
58 for (s = str; *s; s++) {
59 if (*s == ' ')
60 *s = ',';
61 if (*s == ',')
62 n++;
63 }
64 r = ereallocarray(NULL, n, sizeof(*r));
65 for (s = str; n; n--, s++) {
66 r->min = (*s == '-') ? 1 : strtoul(s, &s, 10);
67 r->max = (*s == '-') ? strtoul(s + 1, &s, 10) : r->min;
68 r->next = NULL;
69 if (!r->min || (r->max && r->max < r->min) || (*s && *s != ','))
70 eprintf("bad list value\n");
71 insert(r++);
72 }
73}
74
75static size_t
76seek(struct line *s, size_t pos, size_t *prev, size_t count)
77{
78 size_t n = pos - *prev, i, j;
79
80 if (mode == 'b') {
81 if (n >= s->len)
82 return s->len;
83 if (nflag)
84 while (n && !UTF8_POINT(s->data[n]))
85 n--;
86 *prev += n;
87 return n;
88 } else if (mode == 'c') {
89 for (n++, i = 0; i < s->len; i++)
90 if (UTF8_POINT(s->data[i]) && !--n)
91 break;
92 } else {
93 for (i = (count < delimlen + 1) ? 0 : delimlen; n && i < s->len; ) {
94 if ((s->len - i) >= delimlen &&
95 !memcmp(s->data + i, delim, delimlen)) {
96 if (!--n && count)
97 break;
98 i += delimlen;
99 continue;
100 }
101 for (j = 1; j + i <= s->len && !fullrune(s->data + i, j); j++);
102 i += j;
103 }
104 }
105 *prev = pos;
106
107 return i;
108}
109
110static void
111cut(FILE *fp, const char *fname)
112{
113 Range *r;
114 struct line s;
115 static struct line line;
116 static size_t size;
117 size_t i, n, p;
118 ssize_t len;
119
120 while ((len = getline(&line.data, &size, fp)) > 0) {
121 line.len = len;
122 if (line.data[line.len - 1] == '\n')
123 line.data[--line.len] = '\0';
124 if (mode == 'f' && !memmem(line.data, line.len, delim, delimlen)) {
125 if (!sflag) {
126 fwrite(line.data, 1, line.len, stdout);
127 fputc('\n', stdout);
128 }
129 continue;
130 }
131 for (i = 0, p = 1, s = line, r = list; r; r = r->next) {
132 n = seek(&s, r->min, &p, i);
133 s.data += n;
134 s.len -= n;
135 i += (mode == 'f') ? delimlen : 1;
136 if (!s.len)
137 break;
138 if (!r->max) {
139 fwrite(s.data, 1, s.len, stdout);
140 break;
141 }
142 n = seek(&s, r->max + 1, &p, i);
143 i += (mode == 'f') ? delimlen : 1;
144 if (fwrite(s.data, 1, n, stdout) != n)
145 eprintf("fwrite <stdout>:");
146 s.data += n;
147 s.len -= n;
148 }
149 putchar('\n');
150 }
151 if (ferror(fp))
152 eprintf("getline %s:", fname);
153}
154
155static void
156usage(void)
157{
158 eprintf("usage: %s -b list [-n] [file ...]\n"
159 " %s -c list [file ...]\n"
160 " %s -f list [-d delim] [-s] [file ...]\n",
161 argv0, argv0, argv0);
162}
163
164// ?man cut: cut out fields from lines
165// ?man arguments: -b list [file ...
166// ?man print selected parts of lines from files
167int
168main(int argc, char *argv[])
169{
170 FILE *fp;
171 int ret = 0;
172
173 ARGBEGIN {
174 // ?man -b: specify block size or base directory
175 case 'b':
176 // ?man -c: print count or perform stdout action
177 case 'c':
178 // ?man -f:mode: force the operation
179 case 'f':
180 mode = ARGC();
181 parselist(EARGF(usage()));
182 break;
183 // ?man -d:str: specify directory
184 case 'd':
185 delim = EARGF(usage());
186 if (!*delim)
187 eprintf("empty delimiter\n");
188 delimlen = unescape(delim);
189 break;
190 // ?man -n: print line numbers or counts
191 case 'n':
192 nflag = 1;
193 break;
194 // ?man -s: silent mode or print summary
195 case 's':
196 sflag = 1;
197 break;
198 default:
199 usage();
200 } ARGEND
201
202 if (!mode)
203 usage();
204
205 if (!argc)
206 cut(stdin, "<stdin>");
207 else {
208 for (; *argv; argc--, argv++) {
209 if (!strcmp(*argv, "-")) {
210 *argv = "<stdin>";
211 fp = stdin;
212 } else if (!(fp = fopen(*argv, "r"))) {
213 weprintf("fopen %s:", *argv);
214 ret = 1;
215 continue;
216 }
217 cut(fp, *argv);
218 if (fp != stdin && fshut(fp, *argv))
219 ret = 1;
220 }
221 }
222
223 ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>");
224
225 return ret;
226}
