OSX/utilities/src/fileIo.c

   1 /*
   2  * Copyright (c) 2005-2007,2010,2012-2013 Apple Inc. All Rights Reserved.
   3  */
   4
   5 #include <unistd.h>
   6 #include <fcntl.h>
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/types.h>
  11 #include <sys/stat.h>
  12 #include <stdint.h>
  13 #include "fileIo.h"
  14
  15 int writeFile(
  16               const char                        *fileName,
  17               const unsigned char       *bytes,
  18               unsigned              numBytes)
  19 {
  20     size_t n = numBytes;
  21     return writeFileSizet(fileName, bytes, n);
  22 }
  23
  24 int writeFileSizet(
  25         const char                      *fileName,
  26         const unsigned char     *bytes,
  27         size_t              numBytes)
  28 {
  29         int             rtn;
  30         int     fd;
  31     ssize_t wrc;
  32
  33     if (!fileName) {
  34         fwrite(bytes, 1, numBytes, stdout);
  35         fflush(stdout);
  36         return ferror(stdout);
  37     }
  38
  39         fd = open(fileName, O_RDWR | O_CREAT | O_TRUNC, 0600);
  40     if(fd == -1) {
  41                 return errno;
  42         }
  43         wrc = write(fd, bytes, (size_t)numBytes);
  44         if(wrc != (ssize_t) numBytes) {
  45                 if(wrc >= 0) {
  46                         fprintf(stderr, "writeFile: short write\n");
  47                 }
  48                 rtn = EIO;
  49         }
  50         else {
  51                 rtn = 0;
  52         }
  53         close(fd);
  54         return rtn;
  55 }
  56
  57 /*
  58  * Read entire file.
  59  */
  60 int readFileSizet(
  61         const char              *fileName,
  62         unsigned char   **bytes,                // mallocd and returned
  63         size_t          *numBytes)              // returned
  64 {
  65         int rtn;
  66         int fd;
  67         char *buf;
  68         struct stat     sb;
  69         size_t size;
  70     ssize_t rrc;
  71
  72         *numBytes = 0;
  73         *bytes = NULL;
  74         fd = open(fileName, O_RDONLY);
  75     if(fd == -1) {
  76                 return errno;
  77         }
  78         rtn = fstat(fd, &sb);
  79         if(rtn) {
  80                 goto errOut;
  81         }
  82         if (sb.st_size > (off_t) ((UINT32_MAX >> 1)-1)) {
  83                 rtn = EFBIG;
  84                 goto errOut;
  85         }
  86         size = (size_t)sb.st_size;
  87         buf = (char *)malloc(size);
  88         if(buf == NULL) {
  89                 rtn = ENOMEM;
  90                 goto errOut;
  91         }
  92         rrc = read(fd, buf, size);
  93         if(rrc != (ssize_t) size) {
  94                 if(rtn >= 0) {
  95             free(buf);
  96                         fprintf(stderr, "readFile: short read\n");
  97                 }
  98                 rtn = EIO;
  99         }
 100         else {
 101                 rtn = 0;
 102                 *bytes = (unsigned char *)buf;
 103                 *numBytes = size;
 104         }
 105
 106 errOut:
 107         close(fd);
 108         return rtn;
 109 }