diff options
Diffstat (limited to 'watch.c')
| -rw-r--r-- | watch.c | 108 |
1 files changed, 66 insertions, 42 deletions
@@ -8,70 +8,94 @@ #include <sys/types.h> #include <sys/event.h> #include <sys/time.h> +#include <sys/resource.h> -#define try(x) if ((x) != -1) {} +#define LIMIT 256 -bool initial = false; /* print one initial line at startup */ +bool initial = false; // print one initial line at startup int main(int argc, char *argv[]) { - size_t file = 1; /* argv index */ + char **filenames; + int first_file_index, kq; + size_t file_count; + struct kevent changes[LIMIT]; + struct kevent events[LIMIT]; + struct rlimit rlp; + + file_count = argc - 1; + first_file_index = 1; // index of first file argument setbuf(stdout, NULL); // disable buffering even non-interactively - if (argc < 2) goto usage; - if (argc == 3) { - if (strncmp(argv[1], "-i", 2) == 0) { - file = 2; + if (argc < 2) goto usage; // quit if no arguments + if (argv[1][0] == '-') { + if (argc < 3) goto usage; // quit if no filenames + + /* adjust indices */ + file_count = argc - 2; + first_file_index = 2; + + if (strcmp(argv[1], "-i") == 0) initial = true; - } else { + else goto usage; - } } - int fd; - try (fd = open(argv[file], O_RDONLY)) else err(1, "%s", argv[file]); + if (file_count > LIMIT) + errx(1, "more than %d files", LIMIT); - if (initial) - printf("%s\n", argv[file]); + if ((kq = kqueue()) == -1) err(1, "kqueue"); - try (pledge("stdio", NULL)) else err(1, "pledge"); + /* save filenames by file descriptor */ + if (getrlimit(RLIMIT_NOFILE, &rlp) == -1) + err(1, "getrlimit"); + if ((filenames = reallocarray(NULL, rlp.rlim_max, sizeof(char **))) == NULL) + err(1, "reallocarray"); - int kq; - try (kq = kqueue()) else err(1, "kqueue"); + /* add each file to change list */ + for (int i = first_file_index; i < argc; i++) { + int fd; + if ((fd = open(argv[i], O_RDONLY)) == -1) + err(1, "%s", argv[i]); - struct kevent change = { // event to watch for - .ident = fd, - .filter = EVFILT_VNODE, - .flags = EV_ADD | EV_CLEAR, - .fflags = NOTE_WRITE | NOTE_RENAME | NOTE_DELETE, - .data = 0, - .udata = NULL - }; + filenames[fd] = argv[i]; - // Register event to watch for - try (kevent(kq, &change, 1, NULL, 0, NULL)) else err(1, "kevent"); + if (initial) + printf("%s\n", argv[i]); + + struct kevent change = { // event to watch for + .ident = fd, + .filter = EVFILT_VNODE, + .flags = EV_ADD | EV_CLEAR, + .fflags = NOTE_WRITE | NOTE_DELETE, + .data = 0, + .udata = NULL + }; + + changes[i - first_file_index] = change; + } - if (change.flags & EV_ERROR) - errx(1, "event error: %s", strerror(change.data)); + if (pledge("stdio", NULL) == -1) err(1, "pledge"); - int n; - struct kevent event; - while (1) { - // Wait for event - try (n = kevent(kq, NULL, 0, &event, 1, NULL)) - else err(1, "kevent wait"); + for (;;) { + int n; + /* register changes and wait for events */ + if ((n = kevent(kq, changes, file_count, events, file_count, NULL)) == -1) + err(1, "kevent wait"); if (n > 0) { - if (event.fflags & NOTE_WRITE) - printf("%s\n", argv[file]); - if (event.fflags & NOTE_RENAME) - warnx("file was renamed\n"); - if (event.fflags & NOTE_DELETE) - errx(1, "file was deleted\n"); + for (int i = 0; i < n; i++) { + if (events[i].flags & EV_ERROR) + errx(1, "event error: %s", strerror(events[i].data)); + if (events[i].fflags & NOTE_WRITE) + printf("%s\n", filenames[events[i].ident]); + if (events[i].fflags & NOTE_DELETE) + errx(1, "%s was deleted", filenames[events[i].ident]); + } } } - // assume that the kernel closes the file descriptors + return 0; // assume that the kernel closes the file descriptors usage: - errx(1, "usage: %s [-i] file\n", argv[0]); + fprintf(stderr, "usage: %s [-i] file\n", argv[0]); } |