diff options
| -rw-r--r-- | nq.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/nq.c b/nq.c index 83909c8..13a1e5d 100644 --- a/nq.c +++ b/nq.c @@ -1,9 +1,10 @@ /* - * nq CMD... - run CMD... in background and in order, saving output to ,* files + * nq [-w] CMD... - run CMD... in background and in order, saving output + * -w wait for all jobs queued so far to finish * * - requires POSIX.1-2008 * - enforcing order works like this: - * - every job has a flock(2)ed file ala ",TIMESTAMP.PID" + * - every job has a flock(2)ed output file ala ",TIMESTAMP.PID" * - every job starts only after all earlier flock(2)ed files finished * - the lock is released when job terminates * - no sub-second file system time stamps are required, jobs are started @@ -69,19 +70,32 @@ write_execline(int fd, int argc, char *argv[]) int main(int argc, char *argv[]) { - int dirfd, lockfd; + int dirfd = 0, lockfd = 0, opt = 0, wflag = 0; int pipefd[2]; char lockfile[32]; pid_t child; struct timeval started; struct dirent *ent; + DIR *dir; /* timestamp is milliseconds since epoch. */ gettimeofday(&started, NULL); int64_t ms = started.tv_sec*1000 + started.tv_usec/1000; + while ((opt = getopt(argc, argv, "+hw")) != -1) { + switch (opt) { + case 'w': + wflag = 1; + break; + case 'h': + default: + goto usage; + } + } + if (argc <= 1) { - swrite(2, "usage: nq CMD...\n"); +usage: + swrite(2, "usage: nq [-w] CMD...\n"); exit(1); } @@ -95,6 +109,11 @@ main(int argc, char *argv[]) exit(111); } + if (wflag) { + sprintf(lockfile, ".,%011lx.%d", ms, getpid()); + goto wait; + } + pipe(pipefd); /* first fork, parent exits to run in background. */ @@ -173,7 +192,8 @@ main(int argc, char *argv[]) write_execline(lockfd, argc, argv); - DIR *dir = fdopendir(dirfd); +wait: + dir = fdopendir(dirfd); if (!dir) { perror("fdopendir"); exit(111); @@ -205,6 +225,9 @@ again: closedir(dir); /* closes dirfd too. */ + if (wflag) + return 0; + /* ready to run. */ swrite(lockfd, "\n\n"); |