slstatus/util.c
Laslo Hunhold 80fc20d1d6 Add warn() and die()
Given slstatus is a tool that runs in the background, most likely run
from .xinitrc, it's important to prepend the name of the tool to error
messages so it becomes clear where the error is coming from.

To make this much more consistent, this commit adds warn() and die()
utility functions consistent with other suckless projects and adapts all
calls to fprintf(stderr, *) to the warn() and die() functions, greatly
increasing the readability of the code.
2018-05-18 11:13:05 +02:00

85 lines
1.2 KiB
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"
char *argv0;
static void
verr(const char *fmt, va_list ap)
{
if (argv0 && strncmp(fmt, "usage", sizeof("usage") - 1)) {
fprintf(stderr, "%s: ", argv0);
}
vfprintf(stderr, fmt, ap);
if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
fputc(' ', stderr);
perror(NULL);
} else {
fputc('\n', stderr);
}
}
void
warn(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
verr(fmt, ap);
va_end(ap);
}
void
die(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
verr(fmt, ap);
va_end(ap);
exit(1);
}
const char *
bprintf(const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
if ((ret = vsnprintf(buf, sizeof(buf), fmt, ap)) < 0) {
warn("vsnprintf:");
} else if ((size_t)ret >= sizeof(buf)) {
warn("vsnprintf: Output truncated");
}
va_end(ap);
return buf;
}
int
pscanf(const char *path, const char *fmt, ...)
{
FILE *fp;
va_list ap;
int n;
if (!(fp = fopen(path, "r"))) {
warn("fopen '%s':", path);
return -1;
}
va_start(ap, fmt);
n = vfscanf(fp, fmt, ap);
va_end(ap);
fclose(fp);
return (n == EOF) ? -1 : n;
}