util.c

   1 /* See LICENSE file for copyright and license details. */
   2 #include <errno.h>
   3 #include <stdarg.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "util.h"
   9
  10 char *argv0;
  11
  12 static void
  13 verr(const char *fmt, va_list ap)
  14 {
  15         if (argv0 && strncmp(fmt, "usage", sizeof("usage") - 1)) {
  16                 fprintf(stderr, "%s: ", argv0);
  17         }
  18
  19         vfprintf(stderr, fmt, ap);
  20
  21         if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
  22                 fputc(' ', stderr);
  23                 perror(NULL);
  24         } else {
  25                 fputc('\n', stderr);
  26         }
  27 }
  28
  29 void
  30 warn(const char *fmt, ...)
  31 {
  32         va_list ap;
  33
  34         va_start(ap, fmt);
  35         verr(fmt, ap);
  36         va_end(ap);
  37 }
  38
  39 void
  40 die(const char *fmt, ...)
  41 {
  42         va_list ap;
  43
  44         va_start(ap, fmt);
  45         verr(fmt, ap);
  46         va_end(ap);
  47
  48         exit(1);
  49 }
  50
  51 int
  52 esnprintf(char *str, size_t size, const char *fmt, ...)
  53 {
  54         va_list ap;
  55         int ret;
  56
  57         va_start(ap, fmt);
  58         ret = vsnprintf(str, size, fmt, ap);
  59         va_end(ap);
  60
  61         if (ret < 0) {
  62                 warn("snprintf:");
  63                 return -1;
  64         } else if ((size_t)ret >= size) {
  65                 warn("snprintf: Output truncated");
  66                 return -1;
  67         }
  68
  69         return ret;
  70 }
  71
  72 const char *
  73 bprintf(const char *fmt, ...)
  74 {
  75         va_list ap;
  76         int ret;
  77
  78         va_start(ap, fmt);
  79         if ((ret = vsnprintf(buf, sizeof(buf), fmt, ap)) < 0) {
  80                 warn("vsnprintf:");
  81         } else if ((size_t)ret >= sizeof(buf)) {
  82                 warn("vsnprintf: Output truncated");
  83         }
  84         va_end(ap);
  85
  86         return buf;
  87 }
  88
  89 const char *
  90 fmt_human(size_t num, int base)
  91 {
  92         size_t i;
  93         double scaled;
  94         const char *siprefix[] = { "", "k", "M", "G", "T", "P", "E", "Z", "Y" };
  95         const char *iecprefix[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei",
  96                                     "Zi", "Yi" };
  97         char *prefix[9];
  98
  99         if (base == 1000) {
 100                 memcpy(prefix, siprefix, sizeof(prefix));
 101         } else if (base == 1024) {
 102                 memcpy(prefix, iecprefix, sizeof(prefix));
 103         }
 104
 105         scaled = num;
 106         for (i = 0; i < LEN(prefix) && scaled >= 1024; i++) {
 107                 scaled /= base;
 108         }
 109
 110         return bprintf("%.1f%s", scaled, prefix[i]);
 111 }
 112
 113 int
 114 pscanf(const char *path, const char *fmt, ...)
 115 {
 116         FILE *fp;
 117         va_list ap;
 118         int n;
 119
 120         if (!(fp = fopen(path, "r"))) {
 121                 warn("fopen '%s':", path);
 122                 return -1;
 123         }
 124         va_start(ap, fmt);
 125         n = vfscanf(fp, fmt, ap);
 126         va_end(ap);
 127         fclose(fp);
 128
 129         return (n == EOF) ? -1 : n;
 130 }