1 /* 2 * Create a squashfs filesystem. This is a highly compressed read only 3 * filesystem. 4 * 5 * Copyright (c) 2012 6 * Phillip Lougher <phillip (at) squashfs.org.uk> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 2, 11 * or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 21 * 22 * read_file.c 23 */ 24 25 #include <stdio.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <ctype.h> 29 #include <errno.h> 30 31 #include "error.h" 32 33 #define TRUE 1 34 #define FALSE 0 35 #define MAX_LINE 16384 36 37 /* 38 * Read file, passing each line to parse_line() for 39 * parsing. 40 * 41 * Lines can be split across multiple lines using "\". 42 * 43 * Blank lines and comment lines indicated by # are supported. 44 */ 45 int read_file(char *filename, char *type, int (parse_line)(char *)) 46 { 47 FILE *fd; 48 char *def, *err, *line = NULL; 49 int res, size = 0; 50 51 fd = fopen(filename, "r"); 52 if(fd == NULL) { 53 ERROR("Could not open %s device file \"%s\" because %s\n", 54 type, filename, strerror(errno)); 55 return FALSE; 56 } 57 58 while(1) { 59 int total = 0; 60 61 while(1) { 62 int len; 63 64 if(total + (MAX_LINE + 1) > size) { 65 line = realloc(line, size += (MAX_LINE + 1)); 66 if(line == NULL) 67 MEM_ERROR(); 68 } 69 70 err = fgets(line + total, MAX_LINE + 1, fd); 71 if(err == NULL) 72 break; 73 74 len = strlen(line + total); 75 total += len; 76 77 if(len == MAX_LINE && line[total - 1] != '\n') { 78 /* line too large */ 79 ERROR("Line too long when reading " 80 "%s file \"%s\", larger than " 81 "%d bytes\n", type, filename, MAX_LINE); 82 goto failed; 83 } 84 85 /* 86 * Remove '\n' terminator if it exists (the last line 87 * in the file may not be '\n' terminated) 88 */ 89 if(len && line[total - 1] == '\n') { 90 line[-- total] = '\0'; 91 len --; 92 } 93 94 /* 95 * If no line continuation then jump out to 96 * process line. Note, we have to be careful to 97 * check for "\\" (backslashed backslash) and to 98 * ensure we don't look at the previous line 99 */ 100 if(len == 0 || line[total - 1] != '\\' || (len >= 2 && 101 strcmp(line + total - 2, "\\\\") == 0)) 102 break; 103 else 104 total --; 105 } 106 107 if(err == NULL) { 108 if(ferror(fd)) { 109 ERROR("Reading %s file \"%s\" failed " 110 "because %s\n", type, filename, 111 strerror(errno)); 112 goto failed; 113 } 114 115 /* 116 * At EOF, normally we'll be finished, but, have to 117 * check for special case where we had "\" line 118 * continuation and then hit EOF immediately afterwards 119 */ 120 if(total == 0) 121 break; 122 else 123 line[total] = '\0'; 124 } 125 126 /* Skip any leading whitespace */ 127 for(def = line; isspace(*def); def ++); 128 129 /* if line is now empty after skipping characters, skip it */ 130 if(*def == '\0') 131 continue; 132 133 /* if comment line, skip */ 134 if(*def == '#') 135 continue; 136 137 res = parse_line(def); 138 if(res == FALSE) 139 goto failed; 140 } 141 142 fclose(fd); 143 free(line); 144 return TRUE; 145 146 failed: 147 fclose(fd); 148 free(line); 149 return FALSE; 150 } 151
