utils.c

   1 /**
   2  * Author: Humberto Naves (hsnaves@gmail.com)
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <stdarg.h>
   8 #include <string.h>
   9 #include <errno.h>
  10
  11 #include "utils.h"
  12
  13 void report (const char *fmt, ...)
  14 {
  15   va_list ap;
  16   va_start (ap, fmt);
  17   vfprintf (stdout, fmt, ap);
  18   va_end (ap);
  19 }
  20
  21 void error (const char *fmt, ...)
  22 {
  23   va_list ap;
  24   va_start (ap, fmt);
  25   vfprintf (stderr, fmt, ap);
  26   fprintf (stderr, "\n");
  27   va_end (ap);
  28 }
  29
  30 void xerror (const char *fmt, ...)
  31 {
  32   va_list ap;
  33   va_start (ap, fmt);
  34   vfprintf (stderr, fmt, ap);
  35   fprintf (stderr, ": %s\n", strerror (errno));
  36   va_end (ap);
  37 }
  38
  39
  40 void fatal (const char *fmt, ...)
  41 {
  42   va_list ap;
  43   va_start (ap, fmt);
  44   fprintf (stderr, "fatal: ");
  45   vfprintf (stderr, fmt, ap);
  46   fprintf (stderr, "\n");
  47   va_end (ap);
  48   exit (1);
  49 }
  50
  51 void xfatal (const char *fmt, ...)
  52 {
  53   va_list ap;
  54   va_start (ap, fmt);
  55   fprintf (stderr, "fatal: ");
  56   vfprintf (stderr, fmt, ap);
  57   fprintf (stderr, ": %s\n", strerror (errno));
  58   va_end (ap);
  59   exit (1);
  60 }
  61
  62 void *xmalloc (size_t size)
  63 {
  64   void *ptr = malloc (size);
  65   if (!ptr) fatal (__FILE__ ": memory exhausted");
  66   return ptr;
  67 }
  68
  69 void *xrealloc (void *ptr, size_t size)
  70 {
  71   void *nptr = realloc (ptr, size);
  72   if (!nptr) fatal (__FILE__ ": can't realloc");
  73   return nptr;
  74 }
  75
  76
  77 static
  78 int _file_size (FILE *fp, const char *path, size_t *size)
  79 {
  80   long r;
  81
  82   if (fseek (fp, 0L, SEEK_END)) {
  83     xerror (__FILE__ ": can't seek file `%s'", path);
  84     fclose (fp);
  85     return 0;
  86   }
  87
  88   r = ftell (fp);
  89   if (r == -1) {
  90     xerror (__FILE__ ": can't get file size of `%s'", path);
  91     return 0;
  92   }
  93
  94   if (size) *size = (size_t) r;
  95   return 1;
  96 }
  97
  98 void *read_file (const char *path, size_t *size)
  99 {
 100   FILE *fp;
 101   void *buffer;
 102   size_t file_size;
 103   size_t read_return;
 104
 105   fp = fopen (path, "rb");
 106   if (!fp) {
 107     xerror (__FILE__ ": can't open file `%s'", path);
 108     return NULL;
 109   }
 110
 111   if (!_file_size (fp, path, &file_size)) {
 112     return NULL;
 113   }
 114
 115   buffer = xmalloc (file_size);
 116   rewind (fp);
 117
 118   read_return = fread (buffer, 1, file_size, fp);
 119   fclose (fp);
 120
 121   if (read_return != file_size) {
 122     error (__FILE__ ": can't fully read file `%s'", path);
 123     free (buffer);
 124     return NULL;
 125   }
 126
 127   if (size) *size = file_size;
 128   return buffer;
 129 }