1 /*- 2 * Copyright (c) 2008 Tim Kientzle 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "lafe_platform.h" 28 __FBSDID("$FreeBSD$"); 29 30 #include <errno.h> 31 #include <stdio.h> 32 #include <stdlib.h> 33 #include <string.h> 34 35 #include "err.h" 36 #include "line_reader.h" 37 38 #if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__BORLANDC__) 39 #define strdup _strdup 40 #endif 41 42 /* 43 * Read lines from file and do something with each one. If option_null 44 * is set, lines are terminated with zero bytes; otherwise, they're 45 * terminated with newlines. 46 * 47 * This uses a self-sizing buffer to handle arbitrarily-long lines. 48 */ 49 struct lafe_line_reader { 50 FILE *f; 51 char *buff, *buff_end, *line_start, *line_end, *p; 52 char *pathname; 53 size_t buff_length; 54 int nullSeparator; /* Lines separated by null, not CR/CRLF/etc. */ 55 int ret; 56 }; 57 58 struct lafe_line_reader * 59 lafe_line_reader(const char *pathname, int nullSeparator) 60 { 61 struct lafe_line_reader *lr; 62 63 lr = calloc(1, sizeof(*lr)); 64 if (lr == NULL) 65 lafe_errc(1, ENOMEM, "Can't open %s", pathname); 66 67 lr->nullSeparator = nullSeparator; 68 lr->pathname = strdup(pathname); 69 70 if (strcmp(pathname, "-") == 0) 71 lr->f = stdin; 72 else 73 lr->f = fopen(pathname, "r"); 74 if (lr->f == NULL) 75 lafe_errc(1, errno, "Couldn't open %s", pathname); 76 lr->buff_length = 8192; 77 lr->buff = malloc(lr->buff_length); 78 if (lr->buff == NULL) 79 lafe_errc(1, ENOMEM, "Can't read %s", pathname); 80 lr->line_start = lr->line_end = lr->buff_end = lr->buff; 81 82 return (lr); 83 } 84 85 const char * 86 lafe_line_reader_next(struct lafe_line_reader *lr) 87 { 88 size_t bytes_wanted, bytes_read, new_buff_size; 89 char *line_start, *p; 90 91 for (;;) { 92 /* If there's a line in the buffer, return it immediately. */ 93 while (lr->line_end < lr->buff_end) { 94 if (lr->nullSeparator) { 95 if (*lr->line_end == '\0') { 96 line_start = lr->line_start; 97 lr->line_start = lr->line_end + 1; 98 lr->line_end = lr->line_start; 99 return (line_start); 100 } 101 } else if (*lr->line_end == '\x0a' || *lr->line_end == '\x0d') { 102 *lr->line_end = '\0'; 103 line_start = lr->line_start; 104 lr->line_start = lr->line_end + 1; 105 lr->line_end = lr->line_start; 106 if (line_start[0] != '\0') 107 return (line_start); 108 } 109 lr->line_end++; 110 } 111 112 /* If we're at end-of-file, process the final data. */ 113 if (lr->f == NULL) { 114 /* If there's more text, return one last line. */ 115 if (lr->line_end > lr->line_start) { 116 *lr->line_end = '\0'; 117 line_start = lr->line_start; 118 lr->line_start = lr->line_end + 1; 119 lr->line_end = lr->line_start; 120 return (line_start); 121 } 122 /* Otherwise, we're done. */ 123 return (NULL); 124 } 125 126 /* Buffer only has part of a line. */ 127 if (lr->line_start > lr->buff) { 128 /* Move a leftover fractional line to the beginning. */ 129 memmove(lr->buff, lr->line_start, 130 lr->buff_end - lr->line_start); 131 lr->buff_end -= lr->line_start - lr->buff; 132 lr->line_end -= lr->line_start - lr->buff; 133 lr->line_start = lr->buff; 134 } else { 135 /* Line is too big; enlarge the buffer. */ 136 new_buff_size = lr->buff_length * 2; 137 if (new_buff_size <= lr->buff_length) 138 lafe_errc(1, ENOMEM, 139 "Line too long in %s", lr->pathname); 140 lr->buff_length = new_buff_size; 141 p = realloc(lr->buff, new_buff_size); 142 if (p == NULL) 143 lafe_errc(1, ENOMEM, 144 "Line too long in %s", lr->pathname); 145 lr->buff_end = p + (lr->buff_end - lr->buff); 146 lr->line_end = p + (lr->line_end - lr->buff); 147 lr->line_start = lr->buff = p; 148 } 149 150 /* Get some more data into the buffer. */ 151 bytes_wanted = lr->buff + lr->buff_length - lr->buff_end; 152 bytes_read = fread(lr->buff_end, 1, bytes_wanted, lr->f); 153 lr->buff_end += bytes_read; 154 155 if (ferror(lr->f)) 156 lafe_errc(1, errno, "Can't read %s", lr->pathname); 157 if (feof(lr->f)) { 158 if (lr->f != stdin) 159 fclose(lr->f); 160 lr->f = NULL; 161 } 162 } 163 } 164 165 void 166 lafe_line_reader_free(struct lafe_line_reader *lr) 167 { 168 free(lr->buff); 169 free(lr->pathname); 170 free(lr); 171 } 172