diff options
| -rwxr-xr-x | home/.bin/watch.c | 100 | ||||
| -rwxr-xr-x | link.sh | 1 |
2 files changed, 101 insertions, 0 deletions
diff --git a/home/.bin/watch.c b/home/.bin/watch.c new file mode 100755 index 00000000..7720315b --- /dev/null +++ b/home/.bin/watch.c @@ -0,0 +1,100 @@ +#if 0 +exec cc -Wall -Wextra -Wpedantic -o $(dirname $0)/watch $0 +#endif + +/* + * Execute a command each time files change. + * + * Copyright (c) 2017, June McEnroe <programble@gmail.com> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <sys/types.h> + +#include <err.h> +#include <fcntl.h> +#include <stdlib.h> +#include <sys/event.h> +#include <sys/wait.h> +#include <sysexits.h> +#include <unistd.h> + +static void watch(int kq, char *path) { + int fd = open(path, O_RDONLY); + if (fd < 0) err(EX_IOERR, "%s", path); + + struct kevent event = { + .ident = fd, + .filter = EVFILT_VNODE, + .flags = EV_ADD | EV_CLEAR, + .fflags = NOTE_WRITE | NOTE_DELETE, + .udata = path, + }; + int nevents = kevent(kq, &event, 1, NULL, 0, NULL); + if (nevents < 0) err(EX_IOERR, "kevent"); +} + +static void exec(char *const argv[]) { + pid_t pid = fork(); + if (pid < 0) err(EX_OSERR, "fork"); + + if (!pid) { + execvp(argv[0], argv); + err(EX_OSERR, "%s", argv[0]); + } + + int status; + pid = wait(&status); + if (pid < 0) err(EX_OSERR, "wait"); + + if (WIFEXITED(status)) { + warnx("exit %d", WEXITSTATUS(status)); + } else if (WIFSIGNALED(status)) { + warnx("signal %d", WTERMSIG(status)); + } else { + warnx("status %d", status); + } +} + +int main(int argc, char *argv[]) { + if (argc < 3) return EX_USAGE; + + int kq = kqueue(); + if (kq < 0) err(EX_OSERR, "kqueue"); + + int index; + for (index = 1; index < argc - 1; ++index) { + if (argv[index][0] == '-') { + index++; + break; + } + watch(kq, argv[index]); + } + + exec(&argv[index]); + + for (;;) { + struct kevent event; + int nevents = kevent(kq, NULL, 0, &event, 1, NULL); + if (nevents < 0) err(EX_IOERR, "kevent"); + + if (event.fflags & NOTE_DELETE) { + close(event.ident); + watch(kq, event.udata); + } + + exec(&argv[index]); + } +} diff --git a/link.sh b/link.sh index 9d012182..802aec11 100755 --- a/link.sh +++ b/link.sh @@ -30,6 +30,7 @@ link '.bin/sup' link '.bin/tup' link '.bin/up' link '.bin/wake.c' +link '.bin/watch.c' link '.bin/xx.c' link '.config/git/config' link '.config/git/ignore' |