sbase/printf.c
FRIGN bafd41e1cf Add printf(1)
This is a particularly interesting program.
I managed to implement everything according to POSIX except how
octal escapes are specified in the standard, which is yet another
format compared to the one demanded for tr(1).
This not only confuses people, it also adds unnecessary cruft
for no real gain.
So in order to be able to use unescape() easily and for consistency,
I used our initial format \o[oo] instead of \0[ooo].

Marked as optional is UTF-8 support for %c in the POSIX specification.
Given how well-developed libutf has become, doing this here was more
or less trivial, putting us yet again ahead of the competition.
2015-02-15 14:46:58 +01:00

148 lines
3.1 KiB
C

/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "utf.h"
#include "util.h"
static void usage(void)
{
eprintf("%s format [arg ...]\n", argv0);
}
int main(int argc, char *argv[])
{
Rune *rarg;
size_t i, j, argi, lastargi, formatlen, arglen;
long long num;
double dou;
int cooldown = 0, width, precision;
char *format, *tmp, *arg, *fmt;
argv0 = argv[0];
if (argc < 2)
usage();
format = argv[1];
if ((tmp = strstr(format, "\\c"))) {
*tmp = 0;
cooldown = 1;
}
formatlen = unescape(format);
lastargi = 0;
for (i = 0, argi = 2; !cooldown || i < formatlen; i++, i = cooldown ? i : (i % formatlen)) {
if (i == 0) {
if (lastargi == argi)
break;
lastargi = argi;
}
if (format[i] != '%') {
putchar(format[i]);
continue;
}
/* field width */
width = 0;
for (i++; strchr("#-+ 0", format[i]); i++);
if (format[i] == '*') {
if (argi < argc)
width = estrtonum(argv[argi++], 0, INT_MAX);
else
cooldown = 1;
i++;
} else {
j = i;
for (; strchr("+-0123456789", format[i]); i++);
if (j != i) {
tmp = estrndup(format + j, i - j);
tmp[i - j] = 0;
width = estrtonum(tmp, 0, INT_MAX);
free(tmp);
}
}
/* field precision */
precision = 6;
if (format[i] == '.') {
if (format[++i] == '*') {
if (argi < argc)
precision = estrtonum(argv[argi++], 0, INT_MAX);
else
cooldown = 1;
} else {
j = i;
for (; strchr("+-0123456789", format[i]); i++);
if (j != i) {
tmp = estrndup(format + j, i - j);
tmp[i - j] = 0;
precision = estrtonum(tmp, 0, INT_MAX);
free(tmp);
}
}
}
if (format[i] != '%') {
if (argi < argc)
arg = argv[argi++];
else {
arg = "";
cooldown = 1;
}
} else
putchar('%');
switch (format[i]) {
case 'b':
if ((tmp = strstr(arg, "\\c"))) {
*tmp = 0;
argi = argc;
}
unescape(arg);
fputs(arg, stdout);
break;
case 'c':
unescape(arg);
rarg = emalloc((utflen(arg) + 1) * sizeof(*rarg));
utftorunestr(arg, rarg);
efputrune(rarg, stdout, "<stdout>");
free(rarg);
break;
case 's':
fputs(arg, stdout);
break;
case 'd': case 'i': case 'o': case 'u': case 'x': case 'X':
arglen = strlen(arg);
for (j = 0; j < arglen && isspace(arg[j]); j++);
if (arg[j] == '\'' || arg[j] == '\"') {
arg += j + 1;
unescape(arg);
rarg = emalloc((utflen(arg) + 1) * sizeof(*rarg));
utftorunestr(arg, rarg);
num = rarg[0];
} else
num = (strlen(arg) > 0) ? estrtonum(arg, LLONG_MIN, LLONG_MAX) : 0;
fmt = estrdup("%*ll#");
fmt[4] = format[i];
printf(fmt, width, num);
free(fmt);
break;
case 'a': case 'A': case 'e': case 'E': case 'f': case 'F': case 'g': case 'G':
fmt = estrdup("%*.*#");
fmt[4] = format[i];
dou = (strlen(arg) > 0) ? estrtod(arg) : 0;
printf(fmt, width, precision, dou);
free(fmt);
break;
default:
eprintf("Invalid format specifier '%c'.\n", format[i]);
}
if (argi >= argc)
cooldown = 1;
}
return 0;
}