root / mainbox / util.c @ ea46eeca
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#include "util.h" |
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#include "log.h" |
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <errno.h> |
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#include <unistd.h> |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <fcntl.h> |
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#define BUF_SIZE 1024 |
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|
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/*
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* read_file
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*
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* Reads the first line of a file. Returns NULL on error, or a pointer to a
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* malloc'd string which should later be freed.
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*/
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char *read_file(const char *filename) { |
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char buf[BUF_SIZE];
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int len;
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FILE *file; |
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file = fopen(filename, "r");
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if (file == NULL) { |
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log_perror(filename); |
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return NULL; |
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} |
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fgets(buf, BUF_SIZE, file); |
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if (ferror(file)) {
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log_perror(filename); |
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fclose(file); |
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return NULL; |
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} |
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len = strlen(buf); |
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if (len > 0 && buf[len-1] == '\n') |
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buf[len-1] = '\0'; |
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fclose(file); |
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return strdup(buf);
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} |
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/*
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* create_pid_file
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*
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* Creates PIDFILE containing the PID of the current process. Returns 0 if
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* successful, or nonzero if there is an error or it already exists.
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*/
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int create_pid_file() {
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int fd;
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FILE *file; |
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fd = open(PIDFILE, O_CREAT | O_EXCL | O_WRONLY, 0644);
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if (fd < 0) { |
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if (errno == EEXIST)
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fprintf(stderr, "ERROR: tooltron is already running, or the pidfile "
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PIDFILE " is stale");
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else
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log_perror(PIDFILE); |
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return 1; |
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} |
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file = fdopen(fd, "w");
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if (!file) {
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log_perror("fdopen");
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return 1; |
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} |
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fprintf(file, "%d", getpid());
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fclose(file); |
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return 0; |
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} |
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/*
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* remove_pid_file
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*
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* Removes PIDFILE.
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*/
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void remove_pid_file() {
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if (unlink(PIDFILE))
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log_perror(PIDFILE); |
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} |
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/*
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* read_pid_file
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*
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* Returns the integer found in PIDFILE, or 0 if there was an
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* error.
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*/
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pid_t read_pid_file() { |
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FILE *file; |
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int pid;
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file = fopen(PIDFILE, "r");
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if (!file) {
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if (errno == ENOENT)
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fprintf(stderr, "ERROR: tooltron does not appear to be running\n");
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else
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perror(PIDFILE); |
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return 0; |
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} |
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if (fscanf(file, "%d", &pid) != 1) { |
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perror("fscanf");
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fclose(file); |
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return 0; |
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} |
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fclose(file); |
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return pid;
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} |