root / mainbox / util.c @ master
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| 1 | 15928a3d | Tom Mullins | #include "util.h" |
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| 2 | 5e03b78d | Tom Mullins | #include "log.h" |
| 3 | 15928a3d | Tom Mullins | #include <stdlib.h> |
| 4 | #include <stdio.h> |
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| 5 | ea46eeca | Tom Mullins | #include <string.h> |
| 6 | cc7646f9 | Tom Mullins | #include <errno.h> |
| 7 | 15928a3d | Tom Mullins | #include <unistd.h> |
| 8 | #include <sys/types.h> |
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| 9 | #include <sys/stat.h> |
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| 10 | #include <fcntl.h> |
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| 11 | |||
| 12 | ea46eeca | Tom Mullins | #define BUF_SIZE 1024 |
| 13 | |||
| 14 | cc7646f9 | Tom Mullins | /*
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| 15 | * read_file
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| 16 | *
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| 17 | ea46eeca | Tom Mullins | * Reads the first line of a file. Returns NULL on error, or a pointer to a
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| 18 | * malloc'd string which should later be freed.
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| 19 | cc7646f9 | Tom Mullins | */
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| 20 | 15928a3d | Tom Mullins | char *read_file(const char *filename) { |
| 21 | ea46eeca | Tom Mullins | char buf[BUF_SIZE];
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| 22 | int len;
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| 23 | FILE *file; |
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| 24 | |||
| 25 | file = fopen(filename, "r");
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| 26 | if (file == NULL) { |
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| 27 | 13fd9e7e | Tom Mullins | log_perror(filename); |
| 28 | 15928a3d | Tom Mullins | return NULL; |
| 29 | } |
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| 30 | |||
| 31 | e247ef4d | Tom Mullins | if (fgets(buf, BUF_SIZE, file) == NULL && ferror(file)) { |
| 32 | ea46eeca | Tom Mullins | log_perror(filename); |
| 33 | fclose(file); |
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| 34 | 15928a3d | Tom Mullins | return NULL; |
| 35 | } |
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| 36 | |||
| 37 | ea46eeca | Tom Mullins | len = strlen(buf); |
| 38 | if (len > 0 && buf[len-1] == '\n') |
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| 39 | buf[len-1] = '\0'; |
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| 40 | |||
| 41 | fclose(file); |
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| 42 | return strdup(buf);
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| 43 | 15928a3d | Tom Mullins | } |
| 44 | cc7646f9 | Tom Mullins | |
| 45 | /*
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| 46 | * create_pid_file
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| 47 | *
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| 48 | 13fd9e7e | Tom Mullins | * Creates PIDFILE containing the PID of the current process. Returns 0 if
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| 49 | * successful, or nonzero if there is an error or it already exists.
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| 50 | cc7646f9 | Tom Mullins | */
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| 51 | int create_pid_file() {
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| 52 | int fd;
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| 53 | FILE *file; |
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| 54 | |||
| 55 | 13fd9e7e | Tom Mullins | fd = open(PIDFILE, O_CREAT | O_EXCL | O_WRONLY, 0644);
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| 56 | cc7646f9 | Tom Mullins | if (fd < 0) { |
| 57 | if (errno == EEXIST)
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| 58 | fprintf(stderr, "ERROR: tooltron is already running, or the pidfile "
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| 59 | ddd50354 | Tom Mullins | PIDFILE " is stale");
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| 60 | cc7646f9 | Tom Mullins | else
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| 61 | 13fd9e7e | Tom Mullins | log_perror(PIDFILE); |
| 62 | cc7646f9 | Tom Mullins | return 1; |
| 63 | } |
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| 64 | |||
| 65 | file = fdopen(fd, "w");
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| 66 | if (!file) {
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| 67 | log_perror("fdopen");
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| 68 | return 1; |
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| 69 | } |
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| 70 | |||
| 71 | fprintf(file, "%d", getpid());
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| 72 | |||
| 73 | fclose(file); |
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| 74 | return 0; |
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| 75 | } |
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| 76 | |||
| 77 | /*
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| 78 | * remove_pid_file
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| 79 | *
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| 80 | 13fd9e7e | Tom Mullins | * Removes PIDFILE.
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| 81 | cc7646f9 | Tom Mullins | */
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| 82 | void remove_pid_file() {
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| 83 | 13fd9e7e | Tom Mullins | if (unlink(PIDFILE))
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| 84 | log_perror(PIDFILE); |
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| 85 | cc7646f9 | Tom Mullins | } |
| 86 | |||
| 87 | /*
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| 88 | * read_pid_file
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| 89 | *
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| 90 | 13fd9e7e | Tom Mullins | * Returns the integer found in PIDFILE, or 0 if there was an
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| 91 | cc7646f9 | Tom Mullins | * error.
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| 92 | */
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| 93 | pid_t read_pid_file() {
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| 94 | FILE *file; |
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| 95 | int pid;
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| 96 | |||
| 97 | 13fd9e7e | Tom Mullins | file = fopen(PIDFILE, "r");
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| 98 | cc7646f9 | Tom Mullins | if (!file) {
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| 99 | if (errno == ENOENT)
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| 100 | fprintf(stderr, "ERROR: tooltron does not appear to be running\n");
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| 101 | else
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| 102 | 13fd9e7e | Tom Mullins | perror(PIDFILE); |
| 103 | cc7646f9 | Tom Mullins | return 0; |
| 104 | } |
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| 105 | |||
| 106 | if (fscanf(file, "%d", &pid) != 1) { |
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| 107 | perror("fscanf");
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| 108 | fclose(file); |
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| 109 | return 0; |
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| 110 | } |
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| 111 | |||
| 112 | fclose(file); |
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| 113 | return pid;
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| 114 | } |