The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 1 | |
| 2 | /* |
| 3 | * Copyright (C) 2008 The Android Open Source Project |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | #include <stdio.h> |
| 19 | #include <string.h> |
| 20 | #include <fcntl.h> |
| 21 | #include <unistd.h> |
| 22 | #include <malloc.h> |
| 23 | #include <errno.h> |
| 24 | #include <sys/types.h> |
| 25 | #include <sys/stat.h> |
| 26 | #include <unistd.h> |
| 27 | |
| 28 | void *read_file(char *filename, ssize_t *_size) |
| 29 | { |
| 30 | int ret, fd; |
| 31 | struct stat sb; |
| 32 | ssize_t size; |
| 33 | void *buffer = NULL; |
| 34 | |
| 35 | /* open the file */ |
| 36 | fd = open(filename, O_RDONLY); |
| 37 | if (fd < 0) |
| 38 | return NULL; |
| 39 | |
| 40 | /* find out how big it is */ |
| 41 | if (fstat(fd, &sb) < 0) |
| 42 | goto bail; |
| 43 | size = sb.st_size; |
| 44 | |
| 45 | /* allocate memory for it to be read into */ |
| 46 | buffer = malloc(size); |
| 47 | if (!buffer) |
| 48 | goto bail; |
| 49 | |
| 50 | /* slurp it into our buffer */ |
| 51 | ret = read(fd, buffer, size); |
| 52 | if (ret != size) |
| 53 | goto bail; |
| 54 | |
| 55 | /* let the caller know how big it is */ |
| 56 | *_size = size; |
| 57 | |
| 58 | bail: |
| 59 | close(fd); |
| 60 | return buffer; |
| 61 | } |
The Android Open Source Project | f614d64 | 2009-03-18 17:39:49 -0700 | [diff] [blame] | 62 | char *truncate_sysfs_path(char *path, int num_elements_to_remove, char *buffer, int buffer_size) |
The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 63 | { |
| 64 | int i; |
| 65 | |
The Android Open Source Project | f614d64 | 2009-03-18 17:39:49 -0700 | [diff] [blame] | 66 | strncpy(buffer, path, buffer_size); |
The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 67 | |
| 68 | for (i = 0; i < num_elements_to_remove; i++) { |
| 69 | char *p = &buffer[strlen(buffer)-1]; |
| 70 | |
| 71 | for (p = &buffer[strlen(buffer) -1]; *p != '/'; p--); |
| 72 | *p = '\0'; |
| 73 | } |
| 74 | |
| 75 | return buffer; |
| 76 | } |
| 77 | |
| 78 | char *read_sysfs_var(char *buffer, size_t maxlen, char *devpath, char *var) |
| 79 | { |
| 80 | char filename[255]; |
| 81 | char *p; |
| 82 | ssize_t sz; |
| 83 | |
The Android Open Source Project | f614d64 | 2009-03-18 17:39:49 -0700 | [diff] [blame] | 84 | snprintf(filename, sizeof(filename), "/sys%s/%s", devpath, var); |
The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 85 | p = read_file(filename, &sz); |
| 86 | p[(strlen(p) - 1)] = '\0'; |
| 87 | strncpy(buffer, p, maxlen); |
| 88 | free(p); |
| 89 | return buffer; |
| 90 | } |
| 91 | |