sbase/expand.c

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C
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/* See LICENSE file for copyright and license details. */
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
#include "util.h"
typedef struct {
FILE *fp;
const char *name;
} Fdescr;
static int expand(Fdescr *f, int tabstop);
static void
usage(void)
{
eprintf("usage: %s [-t n] [file...]\n", argv0);
}
int
main(int argc, char *argv[])
{
Fdescr dsc;
FILE *fp;
int tabstop = 8;
ARGBEGIN {
case 't':
tabstop = estrtol(EARGF(usage()), 0);
break;
default:
usage();
} ARGEND;
if (argc == 0) {
dsc.name = "<stdin>";
dsc.fp = stdin;
expand(&dsc, tabstop);
} else {
for (; argc > 0; argc--) {
if (!(fp = fopen(*argv, "r"))) {
eprintf("fopen %s:", *argv);
}
dsc.name = *argv;
dsc.fp = fp;
expand(&dsc, tabstop);
fclose(fp);
argv++;
}
}
return 0;
}
static wint_t
in(Fdescr *f)
{
wint_t c = fgetwc(f->fp);
if (c == WEOF && ferror(f->fp))
eprintf("'%s' read error:", f->name);
return c;
}
static void
out(wint_t c)
{
putwchar(c);
if (ferror(stdout))
eprintf("write error:");
}
static int
expand(Fdescr *dsc, int tabstop)
{
int col = 0;
wint_t c;
for (;;) {
c = in(dsc);
if (c == WEOF)
break;
switch (c) {
case '\t':
do {
col++;
out(' ');
} while (col & (tabstop - 1));
break;
case '\b':
if (col)
col--;
out(c);
break;
case '\n':
col = 0;
out(c);
break;
default:
col++;
out(c);
break;
}
}
return 0;
}