add chown

chown.c

@@ -0,0 +1,66 @@
+/* See LICENSE file for copyright and license details. */
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "util.h"
+
+static void chownpwgr(const char *);
+
+static bool rflag = false;
+static struct passwd *pw = NULL;
+static struct group *gr = NULL;
+
+int
+main(int argc, char *argv[])
+{
+	char c, *owner, *group;
+
+	while((c = getopt(argc, argv, "Rr")) != -1)
+		switch(c) {
+		case 'R':
+		case 'r':
+			rflag = true;
+			break;
+		default:
+			exit(EXIT_FAILURE);
+		}
+	if(optind == argc)
+		eprintf("usage: %s [-Rr] [owner][:group] [file...]\n", argv[0]);
+	owner = argv[optind++];
+	if((group = strchr(owner, ':')))
+		*group++ = '\0';
+
+	if(owner && *owner) {
+		errno = 0;
+		pw = getpwnam(owner);
+		if(errno != 0)
+			eprintf("getpwnam %s:", owner);
+		else if(!pw)
+			eprintf("getpwnam %s: no such user\n", owner);
+	}
+	if(group && *group) {
+		errno = 0;
+		gr = getgrnam(group);
+		if(errno != 0)
+			eprintf("getgrnam %s:", group);
+		else if(!gr)
+			eprintf("getgrnam %s: no such user\n", group);
+	}
+	for(; optind < argc; optind++)
+		chownpwgr(argv[optind]);
+	return EXIT_SUCCESS;
+}
+
+void
+chownpwgr(const char *path)
+{
+	if(chown(path, pw ? pw->pw_uid : -1, gr ? gr->gr_gid : -1) != 0)
+		eprintf("chown %s:", path);
+	if(rflag)
+		recurse(path, chownpwgr);
+}