Joe Hershberger | 170ab11 | 2012-12-11 22:16:24 -0600 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2012 |
| 3 | * Joe Hershberger, National Instruments, joe.hershberger@ni.com |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 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 as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, 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, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | |
Joe Hershberger | 30fd4fad | 2012-12-11 22:16:32 -0600 | [diff] [blame] | 24 | #ifdef USE_HOSTCC /* Eliminate "ANSI does not permit..." warnings */ |
| 25 | #include <stdint.h> |
| 26 | #include <stdio.h> |
| 27 | #include <linux/linux_string.h> |
| 28 | #else |
Joe Hershberger | 170ab11 | 2012-12-11 22:16:24 -0600 | [diff] [blame] | 29 | #include <common.h> |
Joe Hershberger | 30fd4fad | 2012-12-11 22:16:32 -0600 | [diff] [blame] | 30 | #endif |
| 31 | |
Joe Hershberger | 170ab11 | 2012-12-11 22:16:24 -0600 | [diff] [blame] | 32 | #include <env_attr.h> |
| 33 | #include <errno.h> |
| 34 | #include <linux/string.h> |
| 35 | #include <malloc.h> |
| 36 | |
| 37 | /* |
| 38 | * Iterate through the whole list calling the callback for each found element. |
| 39 | * "attr_list" takes the form: |
| 40 | * attributes = [^,:\s]* |
| 41 | * entry = name[:attributes] |
| 42 | * list = entry[,list] |
| 43 | */ |
| 44 | int env_attr_walk(const char *attr_list, |
| 45 | int (*callback)(const char *name, const char *attributes)) |
| 46 | { |
| 47 | const char *entry, *entry_end; |
| 48 | char *name, *attributes; |
| 49 | |
| 50 | if (!attr_list) |
| 51 | /* list not found */ |
| 52 | return 1; |
| 53 | |
| 54 | entry = attr_list; |
| 55 | do { |
| 56 | char *entry_cpy = NULL; |
| 57 | |
| 58 | entry_end = strchr(entry, ENV_ATTR_LIST_DELIM); |
| 59 | /* check if this is the last entry in the list */ |
| 60 | if (entry_end == NULL) { |
| 61 | int entry_len = strlen(entry); |
| 62 | |
| 63 | if (entry_len) { |
| 64 | /* |
| 65 | * allocate memory to copy the entry into since |
| 66 | * we will need to inject '\0' chars and squash |
| 67 | * white-space before calling the callback |
| 68 | */ |
| 69 | entry_cpy = malloc(entry_len + 1); |
| 70 | if (entry_cpy) |
| 71 | /* copy the rest of the list */ |
| 72 | strcpy(entry_cpy, entry); |
| 73 | else |
| 74 | return -ENOMEM; |
| 75 | } |
| 76 | } else { |
| 77 | int entry_len = entry_end - entry; |
| 78 | |
| 79 | if (entry_len) { |
| 80 | /* |
| 81 | * allocate memory to copy the entry into since |
| 82 | * we will need to inject '\0' chars and squash |
| 83 | * white-space before calling the callback |
| 84 | */ |
| 85 | entry_cpy = malloc(entry_len + 1); |
| 86 | if (entry_cpy) { |
| 87 | /* copy just this entry and null term */ |
| 88 | strncpy(entry_cpy, entry, entry_len); |
| 89 | entry_cpy[entry_len] = '\0'; |
| 90 | } else |
| 91 | return -ENOMEM; |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | /* check if there is anything to process (e.g. not ",,,") */ |
| 96 | if (entry_cpy != NULL) { |
| 97 | attributes = strchr(entry_cpy, ENV_ATTR_SEP); |
| 98 | /* check if there is a ':' */ |
| 99 | if (attributes != NULL) { |
| 100 | /* replace the ':' with '\0' to term name */ |
| 101 | *attributes++ = '\0'; |
| 102 | /* remove white-space from attributes */ |
| 103 | attributes = strim(attributes); |
| 104 | } |
| 105 | /* remove white-space from name */ |
| 106 | name = strim(entry_cpy); |
| 107 | |
| 108 | /* only call the callback if there is a name */ |
| 109 | if (strlen(name) != 0) { |
| 110 | int retval = 0; |
| 111 | |
| 112 | retval = callback(name, attributes); |
| 113 | if (retval) { |
| 114 | free(entry_cpy); |
| 115 | return retval; |
| 116 | } |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | free(entry_cpy); |
| 121 | entry = entry_end + 1; |
| 122 | } while (entry_end != NULL); |
| 123 | |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * Search for the last matching string in another string with the option to |
| 129 | * start looking at a certain point (i.e. ignore anything beyond that point). |
| 130 | */ |
| 131 | static char *reverse_strstr(const char *searched, const char *search_for, |
| 132 | const char *searched_start) |
| 133 | { |
| 134 | char *result = NULL; |
| 135 | |
| 136 | if (*search_for == '\0') |
| 137 | return (char *)searched; |
| 138 | |
| 139 | for (;;) { |
| 140 | char *match = strstr(searched, search_for); |
| 141 | |
| 142 | /* |
| 143 | * Stop looking if no new match is found or looking past the |
| 144 | * searched_start pointer |
| 145 | */ |
| 146 | if (match == NULL || (searched_start != NULL && |
| 147 | match + strlen(search_for) > searched_start)) |
| 148 | break; |
| 149 | |
| 150 | result = match; |
| 151 | searched = match + 1; |
| 152 | } |
| 153 | |
| 154 | return result; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * Retrieve the attributes string associated with a single name in the list |
| 159 | * There is no protection on attributes being too small for the value |
| 160 | */ |
| 161 | int env_attr_lookup(const char *attr_list, const char *name, char *attributes) |
| 162 | { |
| 163 | const char *entry = NULL; |
| 164 | |
| 165 | if (!attributes) |
| 166 | /* bad parameter */ |
| 167 | return -1; |
| 168 | if (!attr_list) |
| 169 | /* list not found */ |
| 170 | return 1; |
| 171 | |
| 172 | entry = reverse_strstr(attr_list, name, NULL); |
| 173 | while (entry != NULL) { |
| 174 | const char *prevch = entry - 1; |
| 175 | const char *nextch = entry + strlen(name); |
| 176 | |
| 177 | /* Skip spaces */ |
| 178 | while (*prevch == ' ') |
| 179 | prevch--; |
| 180 | while (*nextch == ' ') |
| 181 | nextch++; |
| 182 | |
| 183 | /* check for an exact match */ |
| 184 | if ((entry == attr_list || |
| 185 | *prevch == ENV_ATTR_LIST_DELIM) && |
| 186 | (*nextch == ENV_ATTR_SEP || |
| 187 | *nextch == ENV_ATTR_LIST_DELIM || |
| 188 | *nextch == '\0')) |
| 189 | break; |
| 190 | |
| 191 | entry = reverse_strstr(attr_list, name, entry); |
| 192 | } |
| 193 | if (entry != NULL) { |
| 194 | int len; |
| 195 | |
| 196 | /* skip the name */ |
| 197 | entry += strlen(name); |
| 198 | /* skip spaces */ |
| 199 | while (*entry == ' ') |
| 200 | entry++; |
| 201 | if (*entry != ENV_ATTR_SEP) |
| 202 | len = 0; |
| 203 | else { |
| 204 | const char *delim; |
| 205 | static const char delims[] = { |
| 206 | ENV_ATTR_LIST_DELIM, ' ', '\0'}; |
| 207 | |
| 208 | /* skip the attr sep */ |
| 209 | entry += 1; |
| 210 | /* skip spaces */ |
| 211 | while (*entry == ' ') |
| 212 | entry++; |
| 213 | |
| 214 | delim = strpbrk(entry, delims); |
| 215 | if (delim == NULL) |
| 216 | len = strlen(entry); |
| 217 | else |
| 218 | len = delim - entry; |
| 219 | memcpy(attributes, entry, len); |
| 220 | } |
| 221 | attributes[len] = '\0'; |
| 222 | |
| 223 | /* success */ |
| 224 | return 0; |
| 225 | } |
| 226 | |
| 227 | /* not found in list */ |
| 228 | return 2; |
| 229 | } |