file_util.c

   1 /* file_util.c - convenience routines for common stat operations
   2
   3    Carl D. Worth
   4
   5    Copyright (C) 2001 University of Southern California
   6
   7    This program is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU General Public License as
   9    published by the Free Software Foundation; either version 2, or (at
  10    your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    General Public License for more details.
  16 */
  17
  18 #include "opkg.h"
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21
  22 #include "sprintf_alloc.h"
  23 #include "file_util.h"
  24 #include "md5.h"
  25 #include "libbb/libbb.h"
  26 #undef strlen
  27
  28 int file_exists(const char *file_name)
  29 {
  30     int err;
  31     struct stat stat_buf;
  32
  33     err = stat(file_name, &stat_buf);
  34     if (err == 0) {
  35         return 1;
  36     } else {
  37         return 0;
  38     }
  39 }
  40
  41 int file_is_dir(const char *file_name)
  42 {
  43     int err;
  44     struct stat stat_buf;
  45
  46     err = stat(file_name, &stat_buf);
  47     if (err) {
  48         return 0;
  49     }
  50
  51     return S_ISDIR(stat_buf.st_mode);
  52 }
  53
  54 /* read a single line from a file, stopping at a newline or EOF.
  55    If a newline is read, it will appear in the resulting string.
  56    Return value is a malloc'ed char * which should be freed at
  57    some point by the caller.
  58
  59    Return value is NULL if the file is at EOF when called.
  60 */
  61 #define FILE_READ_LINE_BUF_SIZE 1024
  62 char *file_read_line_alloc(FILE *file)
  63 {
  64     char buf[FILE_READ_LINE_BUF_SIZE];
  65     int buf_len;
  66     char *line = NULL;
  67     int line_size = 0;
  68
  69     memset(buf, 0, FILE_READ_LINE_BUF_SIZE);
  70     while (fgets(buf, FILE_READ_LINE_BUF_SIZE, file)) {
  71         buf_len = strlen(buf);
  72         if (line) {
  73             line_size += buf_len;
  74             line = realloc(line, line_size);
  75             if (line == NULL) {
  76                 fprintf(stderr, "%s: out of memory\n", __FUNCTION__);
  77                 break;
  78             }
  79             strcat(line, buf);
  80         } else {
  81             line_size = buf_len + 1;
  82             line = strdup(buf);
  83         }
  84         if (buf[buf_len - 1] == '\n') {
  85             break;
  86         }
  87     }
  88
  89     return line;
  90 }
  91
  92 int file_move(const char *src, const char *dest)
  93 {
  94     int err;
  95
  96     err = rename(src, dest);
  97
  98     if (err && errno == EXDEV) {
  99         err = file_copy(src, dest);
 100         unlink(src);
 101     } else if (err) {
 102         fprintf(stderr, "%s: ERROR: failed to rename %s to %s: %s\n",
 103                 __FUNCTION__, src, dest, strerror(errno));
 104     }
 105
 106     return err;
 107 }
 108
 109 /* I put these here to keep libbb dependencies from creeping all over
 110    the opkg code */
 111 int file_copy(const char *src, const char *dest)
 112 {
 113     int err;
 114
 115     err = copy_file(src, dest, FILEUTILS_FORCE | FILEUTILS_PRESERVE_STATUS);
 116     if (err) {
 117         fprintf(stderr, "%s: ERROR: failed to copy %s to %s\n",
 118                 __FUNCTION__, src, dest);
 119     }
 120
 121     return err;
 122 }
 123
 124 int file_mkdir_hier(const char *path, long mode)
 125 {
 126     return make_directory(path, mode, FILEUTILS_RECUR);
 127 }
 128
 129 char *file_md5sum_alloc(const char *file_name)
 130 {
 131     static const int md5sum_bin_len = 16;
 132     static const int md5sum_hex_len = 32;
 133
 134     static const unsigned char bin2hex[16] = {
 135         '0', '1', '2', '3',
 136         '4', '5', '6', '7',
 137         '8', '9', 'a', 'b',
 138         'c', 'd', 'e', 'f'
 139     };
 140
 141     int i, err;
 142     FILE *file;
 143     unsigned char *md5sum_hex;
 144     unsigned char md5sum_bin[md5sum_bin_len];
 145
 146     md5sum_hex = malloc(md5sum_hex_len + 1);
 147     if (md5sum_hex == NULL) {
 148         fprintf(stderr, "%s: out of memory\n", __FUNCTION__);
 149         return strdup("");
 150     }
 151
 152     file = fopen(file_name, "r");
 153     if (file == NULL) {
 154         fprintf(stderr, "%s: Failed to open file %s: %s\n",
 155                 __FUNCTION__, file_name, strerror(errno));
 156         return strdup("");
 157     }
 158
 159     err = md5_stream(file, md5sum_bin);
 160     if (err) {
 161         fprintf(stderr, "%s: ERROR computing md5sum for %s: %s\n",
 162                 __FUNCTION__, file_name, strerror(err));
 163         return strdup("");
 164     }
 165
 166     fclose(file);
 167
 168     for (i=0; i < md5sum_bin_len; i++) {
 169         md5sum_hex[i*2] = bin2hex[md5sum_bin[i] >> 4];
 170         md5sum_hex[i*2+1] = bin2hex[md5sum_bin[i] & 0xf];
 171     }
 172
 173     md5sum_hex[md5sum_hex_len] = '\0';
 174
 175     return md5sum_hex;
 176 }
 177