scron

simple cron daemon
git clone git://git.2f30.org/scron.git
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commit 8bf3c08cb9040bc7f2782dead562637b32ec409b
parent f0a0759a99de22cbc83eef90f4e3bf98bf094213
Author: Ari Malinen <ari.malinen@gmail.com>
Date:   Wed Jun 11 04:03:54 +0300

better arg parsing, error handling and commenting

Diffstat:
Makefile | 2+-
README | 8++++----
dcron.c | 50+++++++++++++++++++++++++++++++++++---------------
3 files changed, 40 insertions(+), 20 deletions(-)
diff --git a/Makefile b/Makefile @@ -1,4 +1,4 @@ -CFLAGS=-O2 -Wall +CFLAGS=-std=c99 -Wall -Wpedantic -Wextra all: dcron diff --git a/README b/README @@ -5,10 +5,10 @@ Single daemon, config and initscript. Logs to stdout and syslog. usage: -usage: dcron [options] --h help --d daemon --f <file> config file +usage: ./dcron [options] +-h help +-d daemon +-f <file> config file config: # min,hour,mday,mon,wday,command diff --git a/dcron.c b/dcron.c @@ -9,14 +9,19 @@ #define MAXLEN 100 #define SLEEP 60 +// config file location char config[MAXLEN+1] = "/etc/dcron.conf"; +// implicit declaration of function 'daemon' +int daemon(int nochdir, int noclose); + int main(int argc, char *argv[]) { FILE *fp; + char *argv0; char line[MAXLEN+1]; + char cmd[MAXLEN+1]; char *col; int min, hour, mday, mon, wday; - char cmd[MAXLEN+1]; int i; time_t t; struct tm *tm; @@ -24,25 +29,35 @@ int main(int argc, char *argv[]) { openlog(argv[0], LOG_CONS | LOG_PID, LOG_LOCAL1); syslog(LOG_NOTICE, "start uid:%d", getuid()); - if (argc > 1 && !strcmp("-h", argv[1])) { - fprintf(stderr, "usage: %s [options]\n\n", argv[0]); + // parse commandline arguments + for (argv0 = *argv; argc > 0; argc--, argv++) { + if (!strcmp("-h", argv[0])) { + fprintf(stderr, "usage: %s [options]\n\n", argv0); - fprintf(stderr, "-h\t\thelp\n"); - fprintf(stderr, "-d\t\tdaemon\n"); - fprintf(stderr, "-f <file>\tconfig file\n"); - return 1; - } else if (argc > 1 && !strcmp("-d", argv[1])) { - if (daemon(1, 0) != 0) { - fprintf(stderr, "error: failed to daemonize\n"); - syslog(LOG_NOTICE, "error: failed to daemonize"); + fprintf(stderr, "-h help\n"); + fprintf(stderr, "-d daemon\n"); + fprintf(stderr, "-f <file> config file\n"); return 1; + } else if (!strcmp("-d", argv[0])) { + if (daemon(1, 0) != 0) { + fprintf(stderr, "error: failed to daemonize\n"); + syslog(LOG_NOTICE, "error: failed to daemonize"); + return 1; + } + } else if (!strcmp("-f", argv[0])) { + if (argv[1][0] == '-') { + fprintf(stderr, "error: -f needs parameter\n"); + syslog(LOG_NOTICE, "error: -f needs parameter"); + break; + } + strncpy(config, argv[1], MAXLEN); + printf("config: %s\n", config); + syslog(LOG_NOTICE, "config: %s", config); + argc--, argv++; } - } else if (argc > 2 && !strcmp("-f", argv[1])) { - strncpy(config, argv[2], MAXLEN); - printf("config: %s\n", config); - syslog(LOG_NOTICE, "config: %s", config); } + // main loop while (1) { t = time(NULL); tm = localtime(&t); @@ -56,8 +71,11 @@ int main(int argc, char *argv[]) { continue; } + // get next line from config while (fgets(line, MAXLEN, fp) != NULL) { + // skip comments and empty lines if (line[1] != '\0' && line[0] != '\043') { + // split line to columns col = strtok(line,"\t"); i = 0; while (col != NULL) { @@ -100,6 +118,7 @@ int main(int argc, char *argv[]) { i++; } + // skip task if any column is unset if (min == 0 || hour == 0 || mday == 0 || mon == 0 || wday == 0 || cmd[0] == '\0' || cmd[1] == '\0') { fprintf(stderr, "error: %s line %d\n", config, i); @@ -108,6 +127,7 @@ int main(int argc, char *argv[]) { continue; } + // run task if date matches if ((min == -1 || min == tm->tm_min) && (hour == -1 || hour == tm->tm_hour) && (mday == -1 || mday == tm->tm_mday) &&