1 files changed, 130 insertions, 0 deletions
diff --git a/rwc.c b/rwc.c
new file mode 100644
index 0000000..3b00d9b
--- /dev/null
+++ b/rwc.c
@@ -0,0 +1,130 @@
+// rwc [-0d] [PATH...] - report when changed
+//   -0  use NUL instead of newline for input/output separator
+//   -d  detect deletions too (prefixed with "- ")
+
+#include <sys/inotify.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <libgen.h>
+#include <search.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+char *argv0;
+char ibuf[8192];
+int ifd;
+
+int dflag;
+char input_delim = '\n';
+
+static void *root = 0; // tree
+
+int
+order(const void *a, const void *b)
+{
+	return strcmp((char *)a, (char*)b);
+}
+
+void
+add(char *file)
+{
+        struct stat st;
+
+	char *dir = file;
+
+	tsearch(strdup(file), &root, order);
+
+	// assume non-existing files are regular files
+	if (lstat(file, &st) < 0 || !S_ISDIR(st.st_mode))
+		dir = dirname(file);
+
+	if (inotify_add_watch(ifd, dir, IN_MOVED_TO | IN_CLOSE_WRITE | dflag)<0)
+		fprintf(stderr, "%s: inotify_add_watch: %s: %s\n",
+		    argv0, dir, strerror(errno));
+}
+
+int
+main(int argc, char *argv[])
+{
+	int c, i;
+
+	argv0 = argv[0];
+
+        while ((c = getopt(argc, argv, "0d")) != -1)
+		switch(c) {
+		case '0': input_delim = 0; break;
+		case 'd': dflag = IN_DELETE | IN_DELETE_SELF; break;
+		default:
+                        fprintf(stderr, "Usage: %s [-0d] [PATH...]\n", argv0);
+                        exit(2);
+                }
+
+        ifd = inotify_init();
+        if (ifd < 0) {
+		fprintf(stderr, "%s: inotify_init: %s\n",
+		    argv0, strerror(errno));
+                exit(111);
+	}
+
+	i = optind;
+	if (optind == argc)
+		goto from_stdin;
+	for (; i < argc; i++) {
+		if (strcmp(argv[i], "-") != 0) {
+			add(argv[i]);
+			continue;
+		}
+from_stdin:
+		while (1) {
+			char *line = 0;
+			size_t linelen = 0;
+			ssize_t rd;
+
+			errno = 0;
+			rd = getdelim(&line, &linelen, input_delim, stdin);
+			if (rd == -1) {
+				if (errno != 0)
+					return -1;
+				break;
+			}
+			
+			if (rd > 0 && line[rd-1] == input_delim)
+				line[rd-1] = 0;  // strip delimiter
+
+			add(line);
+		}
+	}
+
+	while (1) {
+		ssize_t len, i;
+		struct inotify_event *ev;
+
+		len = read(ifd, ibuf, sizeof ibuf);
+		if (len <= 0) {
+			fprintf(stderr, "%s: error reading inotify buffer: %s",
+			    argv0, strerror(errno));
+			exit(1);
+		}
+	
+		for (i = 0; i < len; i += sizeof (*ev) + ev->len) {
+			ev = (struct inotify_event *) (ibuf + i);
+
+			if (ev->mask & IN_IGNORED)
+				continue;
+
+			if (tfind(ev->name, &root, order) ||
+			    tfind(dirname(ev->name), &root, order)) {
+				printf("%s%s%c",
+				    (ev->mask & IN_DELETE ? "- " : ""),
+				    ev->name,
+				    input_delim);
+				fflush(stdout);
+			}
+		}
+	}
+
+        return 0;
+}