libbb: add skip_dev_pfx()

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

7 files changed, 17 insertions, 21 deletions

diff --git a/e2fsprogs/fsck.c b/e2fsprogs/fsck.c
index 0192f3cdb..7c449e3e7 100644
--- a/e2fsprogs/fsck.c
+++ b/e2fsprogs/fsck.c
@@ -169,12 +169,12 @@ static char *base_device(const char *device)
 	const char *disk;
 	int len;
 #endif
-	cp = str = xstrdup(device);
+	str = xstrdup(device);
 
-	/* Skip over /dev/; if it's not present, give up. */
-	if (strncmp(cp, "/dev/", 5) != 0)
+	/* Skip over "/dev/"; if it's not present, give up */
+	cp = skip_dev_pfx(str);
+	if (cp == str)
 		goto errout;
-	cp += 5;
 
 	/*
 	 * For md devices, we treat them all as if they were all
diff --git a/include/libbb.h b/include/libbb.h
index 357571fd8..976120e72 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -263,6 +263,8 @@ extern void chomp(char *s) FAST_FUNC;
 extern void trim(char *s) FAST_FUNC;
 extern char *skip_whitespace(const char *) FAST_FUNC;
 extern char *skip_non_whitespace(const char *) FAST_FUNC;
+extern char *skip_dev_pfx(const char *tty_name) FAST_FUNC;
+
 extern char *strrstr(const char *haystack, const char *needle) FAST_FUNC;
 
 //TODO: supply a pointer to char[11] buffer (avoid statics)?
diff --git a/init/init.c b/init/init.c
index 481f55167..2eb8f1a54 100644
--- a/init/init.c
+++ b/init/init.c
@@ -568,9 +568,7 @@ static void parse_inittab(void)
 			goto bad_entry;
 		/* turn .*TTY -> /dev/TTY */
 		if (tty[0]) {
-			if (strncmp(tty, "/dev/", 5) == 0)
-				tty += 5;
-			tty = concat_path_file("/dev/", tty);
+			tty = concat_path_file("/dev/", skip_dev_pfx(tty));
 		}
 		new_init_action(1 << action, token[3], tty);
 		if (tty[0])
diff --git a/libbb/skip_whitespace.c b/libbb/skip_whitespace.c
index 7b123261b..f5a61a3cf 100644
--- a/libbb/skip_whitespace.c
+++ b/libbb/skip_whitespace.c
@@ -30,3 +30,10 @@ char* FAST_FUNC skip_non_whitespace(const char *s)
 
 	return (char *) s;
 }
+
+char* FAST_FUNC skip_dev_pfx(const char *tty_name)
+{
+	if (strncmp(tty_name, "/dev/", 5) == 0)
+		tty_name += 5;
+	return (char*)tty_name;
+}
diff --git a/libbb/utmp.c b/libbb/utmp.c
index d6ba336e3..68c358e9a 100644
--- a/libbb/utmp.c
+++ b/libbb/utmp.c
@@ -15,14 +15,6 @@ static void touch(const char *filename)
 		close(open(filename, O_WRONLY | O_CREAT, 0664));
 }
 
-// TODO: move to libbb
-static const char* skip_dev_pfx(const char *tty_name)
-{
-	if (strncmp(tty_name, "/dev/", 5) == 0)
-		tty_name += 5;
-	return tty_name;
-}
-
 void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname)
 {
 	struct utmp utent;
diff --git a/loginutils/login.c b/loginutils/login.c
index bf21d6121..078cd68ed 100644
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -249,9 +249,7 @@ int login_main(int argc UNUSED_PARAM, char **argv)
 	full_tty = xmalloc_ttyname(STDIN_FILENO);
 	if (!full_tty)
 		full_tty = xstrdup("UNKNOWN");
-	short_tty = full_tty;
-	if (strncmp(full_tty, "/dev/", 5) == 0)
-		short_tty += 5;
+	short_tty = skip_dev_pfx(full_tty);
 
 	if (opt_host) {
 		fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host);
diff --git a/util-linux/rtcwake.c b/util-linux/rtcwake.c
index 66b08e343..b16376655 100644
--- a/util-linux/rtcwake.c
+++ b/util-linux/rtcwake.c
@@ -35,9 +35,8 @@ static NOINLINE bool may_wakeup(const char *rtcname)
 	ssize_t ret;
 	char buf[128];
 
-	/* strip the '/dev/' from the rtcname here */
-	if (!strncmp(rtcname, "/dev/", 5))
-		rtcname += 5;
+	/* strip "/dev/" from the rtcname here */
+	rtcname = skip_dev_pfx(rtcname);
 
 	snprintf(buf, sizeof(buf), SYS_RTC_PATH, rtcname);
 	ret = open_read_close(buf, buf, sizeof(buf));