battery: fixed remaining time on connected AC

[slstatus.git] / util.c

diff --git a/util.c b/util.c
index 8808aba..08f14ff 100644 (file)
--- a/util.c
+++ b/util.c
@@ -2,23 +2,65 @@
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "util.h"
 
-const char *
-bprintf(const char *fmt, ...)
+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;
-       size_t len;
 
        va_start(ap, fmt);
-       len = vsnprintf(buf, sizeof(buf) - 1, fmt, ap);
+       verr(fmt, ap);
        va_end(ap);
 
-       if (len >= sizeof(buf)) {
-               buf[sizeof(buf)-1] = '\0';
+       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;
 }
@@ -31,7 +73,7 @@ pscanf(const char *path, const char *fmt, ...)
        int n;
 
        if (!(fp = fopen(path, "r"))) {
-               fprintf(stderr, "fopen '%s': %s\n", path, strerror(errno));
+               warn("fopen '%s':", path);
                return -1;
        }
        va_start(ap, fmt);