morpheus-base

morpheus base system
git clone git://git.2f30.org/morpheus-base.git
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cut.c (3174B)


      1 /* See LICENSE file for copyright and license details. */
      2 #include <stdio.h>
      3 #include <stdlib.h>
      4 #include <string.h>
      5 
      6 #include "text.h"
      7 #include "util.h"
      8 
      9 typedef struct Range {
     10 	size_t min, max;
     11 	struct Range *next;
     12 } Range;
     13 
     14 static Range *list = NULL;
     15 static char mode = 0;
     16 static char delim = '\t';
     17 static int nflag = 0;
     18 static int sflag = 0;
     19 
     20 static void
     21 insert(Range *r)
     22 {
     23 	Range *l, *p, *t;
     24 
     25 	for (p = NULL, l = list; l; p = l, l = l->next) {
     26 		if (r->max && r->max + 1 < l->min) {
     27 			r->next = l;
     28 			break;
     29 		} else if (!l->max || r->min < l->max + 2) {
     30 			l->min = MIN(r->min, l->min);
     31 			for (p = l, t = l->next; t; p = t, t = t->next)
     32 				if (r->max && r->max + 1 < t->min)
     33 					break;
     34 			l->max = (p->max && r->max) ? MAX(p->max, r->max) : 0;
     35 			l->next = t;
     36 			return;
     37 		}
     38 	}
     39 	if (p)
     40 		p->next = r;
     41 	else
     42 		list = r;
     43 }
     44 
     45 static void
     46 parselist(char *str)
     47 {
     48 	char *s;
     49 	size_t n = 1;
     50 	Range *r;
     51 
     52 	for (s = str; *s; s++) {
     53 		if (*s == ' ')
     54 			*s = ',';
     55 		if (*s == ',')
     56 			n++;
     57 	}
     58 	r = emalloc(n * sizeof(Range));
     59 	for (s = str; n; n--, s++) {
     60 		r->min = (*s == '-') ? 1 : strtoul(s, &s, 10);
     61 		r->max = (*s == '-') ? strtoul(s + 1, &s, 10) : r->min;
     62 		r->next = NULL;
     63 		if (!r->min || (r->max && r->max < r->min) || (*s && *s != ','))
     64 			eprintf("cut: bad list value\n");
     65 		insert(r++);
     66 	}
     67 }
     68 
     69 static size_t
     70 seek(const char *s, size_t pos, size_t *prev, size_t count)
     71 {
     72 	const char *t;
     73 	size_t n = pos - *prev;
     74 
     75 	if (mode == 'b') {
     76 		if ((t = memchr(s, 0, n)))
     77 			return t - s;
     78 		if (nflag)
     79 			while (n && !UTF8_POINT(s[n]))
     80 				n--;
     81 		*prev += n;
     82 		return n;
     83 	} else if (mode == 'c') {
     84 		for (n++, t = s; *t; t++)
     85 			if (UTF8_POINT(*t) && !--n)
     86 				break;
     87 	} else {
     88 		for (t = (count < 2) ? s : s + 1; n && *t; t++)
     89 			if (*t == delim && !--n && count)
     90 				break;
     91 	}
     92 	*prev = pos;
     93 	return t - s;
     94 }
     95 
     96 static void
     97 cut(FILE *fp)
     98 {
     99 	static char *buf = NULL;
    100 	static size_t size = 0;
    101 	char *s;
    102 	size_t i, n, p;
    103 	ssize_t len;
    104 	Range *r;
    105 
    106 	while ((len = getline(&buf, &size, fp)) != -1) {
    107 		if (len && buf[len - 1] == '\n')
    108 			buf[len - 1] = '\0';
    109 		if (mode == 'f' && !strchr(buf, delim)) {
    110 			if (!sflag)
    111 				puts(buf);
    112 			continue;
    113 		}
    114 		for (i = 0, p = 1, s = buf, r = list; r; r = r->next, s += n) {
    115 			s += seek(s, r->min, &p, i++);
    116 			if (!*s)
    117 				break;
    118 			if (!r->max) {
    119 				fputs(s, stdout);
    120 				break;
    121 			}
    122 			n = seek(s, r->max + 1, &p, i++);
    123 			if (fwrite(s, 1, n, stdout) != n)
    124 				eprintf("write error:");
    125 		}
    126 		putchar('\n');
    127 	}
    128 }
    129 
    130 static void
    131 usage(void)
    132 {
    133 	eprintf("usage: cut -b list [-n] [file ...]\n"
    134 	        "       cut -c list [file ...]\n"
    135 	        "       cut -f list [-d delim] [-s] [file ...]\n");
    136 }
    137 
    138 int
    139 main(int argc, char *argv[])
    140 {
    141 	FILE *fp;
    142 
    143 	ARGBEGIN {
    144 	case 'b':
    145 	case 'c':
    146 	case 'f':
    147 		mode = ARGC();
    148 		parselist(ARGF());
    149 		break;
    150 	case 'd':
    151 		delim = *ARGF();
    152 		break;
    153 	case 'n':
    154 		nflag = 1;
    155 		break;
    156 	case 's':
    157 		sflag = 1;
    158 		break;
    159 	default:
    160 		usage();
    161 	} ARGEND;
    162 
    163 	if (!mode)
    164 		usage();
    165 
    166 	if (!argc)
    167 		cut(stdin);
    168 	else for (; argc--; argv++) {
    169 		if (!strcmp(*argv, "-"))
    170 			cut(stdin);
    171 		else {
    172 			if (!(fp = fopen(*argv, "r"))) {
    173 				weprintf("fopen %s:", *argv);
    174 				continue;
    175 			}
    176 			cut(fp);
    177 			fclose(fp);
    178 		}
    179 	}
    180 	return 0;
    181 }