sbase/cut.c

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3.0 KiB
C
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2013-10-08 19:39:08 +00:00
/* See LICENSE file for copyright and license details. */
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "text.h"
#include "util.h"
static void
usage(void)
{
eprintf("usage: cut -b list [-n] [file...]\n"
" cut -c list [file...]\n"
" cut -f list [-d delim] [-s] [file...]\n");
}
typedef struct Range {
size_t min, max;
struct Range *next;
} Range;
static Range *list = NULL;
static char mode = 0;
static char delim = '\t';
static bool nflag = false;
static bool sflag = false;
static void
insert(Range *r)
{
Range *l, *p, *t;
for(p = NULL, l = list; l; p = l, l = l->next) {
if(r->max && r->max+1 < l->min) {
r->next = l;
break;
} else if(!l->max || r->min < l->max+2) {
l->min = MIN(r->min, l->min);
for(p = l, t = l->next; t; p = t, t = t->next)
if(r->max && r->max+1 < t->min) break;
l->max = (p->max && r->max) ? MAX(p->max, r->max) : 0;
l->next = t;
return;
}
}
if(p) p->next = r; else list = r;
}
static void
parselist(char *str)
{
char *s;
size_t n = 1;
Range *r;
for(s = str; *s; s++) {
if(*s == ' ') *s = ',';
if(*s == ',') n++;
}
if(!(r = malloc(n * sizeof(Range))))
eprintf("malloc:");
for(s = str; n; n--, s++) {
r->min = (*s == '-') ? 1 : strtoul(s, &s, 10);
r->max = (*s == '-') ? strtoul(s + 1, &s, 10) : r->min;
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r->next = NULL;
if(!r->min || (r->max && r->max < r->min) || (*s && *s != ','))
eprintf("cut: bad list value\n");
insert(r++);
}
}
static size_t
seek(const char *s, size_t pos, size_t *prev, size_t count)
{
const char *t;
size_t n = pos - *prev;
if(mode == 'b') {
if((t = memchr(s, 0, n)))
return t - s;
if(nflag)
while(n && !UTF8_POINT(s[n])) n--;
*prev += n;
return n;
} else if(mode == 'c') {
for(n++, t = s; *t; t++)
if(UTF8_POINT(*t) && !--n) break;
} else {
for(t = (count < 2) ? s : s+1; n && *t; t++)
if(*t == delim && !--n && count) break;
}
*prev = pos;
return t - s;
}
static void
cut(FILE *fp)
{
static char *buf = NULL;
static size_t size = 0;
char *s;
size_t i, n, p;
Range *r;
while(afgets(&buf, &size, fp)) {
if(buf[i = strlen(buf)-1] == '\n')
buf[i] = 0;
if(mode == 'f' && !strchr(buf, delim)) {
if(!sflag)
puts(buf);
continue;
}
for(i = 0, p = 1, s = buf, r = list; r; r = r->next, s += n) {
s += seek(s, r->min, &p, i++);
if(!*s) break;
if(!r->max) {
fputs(s, stdout);
break;
}
n = seek(s, r->max + 1, &p, i++);
if(fwrite(s, 1, n, stdout) != n)
eprintf("write error:");
}
putchar('\n');
}
}
int
main(int argc, char *argv[])
{
FILE *fp;
ARGBEGIN {
case 'b':
case 'c':
case 'f':
mode = ARGC();
parselist(ARGF());
break;
case 'd':
delim = *ARGF();
break;
case 'n':
nflag = true;
break;
case 's':
sflag = true;
break;
default:
usage();
} ARGEND;
if(!mode)
usage();
if(!argc)
cut(stdin);
else for(; argc--; argv++) {
if(!(fp = strcmp(*argv, "-") ? fopen(*argv, "r") : stdin)) {
weprintf("fopen %s:", *argv);
continue;
}
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cut(fp);
fclose(fp);
}
return EXIT_SUCCESS;
}