mount: replace control chars in mountpoint name

For compatibility with coreutils and to avoid complex solutions in
mount output mount replaces control characters with '?'.

Note that the listing mode in mount(8) is in maintenance mode --
findmnt(8) provides more robust and better solutions.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/mount.8 b/sys-utils/mount.8
index 6c222d032dec2b130b98fe2b12b145206d7635c3..fc4622d2b49f6f212f4345c0c17bb927581ad810 100644 (file)
--- a/sys-utils/mount.8
+++ b/sys-utils/mount.8
@@ -115,13 +115,13 @@ options to avoid ambivalent interpretation of the given argument. For example
 
 .B The listing and help.
 .RS
-Three forms of invocation do not actually mount anything:
-.TP
-.B "mount \-h"
-prints a help message
-.TP
-.B "mount \-V"
-prints a version string
+The listing mode is maintained for backward compatibility only.
+
+For more robust and definable output use
+.BR findmnt (8),
+\fBespecially in your scripts\fP. Note that control characters in the
+mountpoint name are replaced with '?'.
+
 .TP
 .BR "mount " [ -l "] [" "-t \fItype\fP" ]
 lists all mounted filesystems (of type

diff --git a/sys-utils/mount.c b/sys-utils/mount.c
index 3b9f2c4b6c8f8b1ec22bd0e1c1b690353bf39238..2d1d2cd413e53cab7c84fec0f193e171559f0a29 100644 (file)
--- a/sys-utils/mount.c
+++ b/sys-utils/mount.c
@@ -30,6 +30,7 @@
 #include <sys/stat.h>
 #include <stdarg.h>
 #include <libmount.h>
+#include <ctype.h>
 
 #include "nls.h"
 #include "c.h"
@@ -130,6 +131,22 @@ static void encrypt_pass_release(struct libmnt_context *cxt
        munlockall();
 }
 
+/*
+ * Replace control chars with '?' to be compatible with coreutils. For more
+ * robust solution use findmnt(1) where we use \x?? hex encoding.
+ */
+static void safe_fputs(const char *data)
+{
+       const char *p;
+
+       for (p = data; p && *p; p++) {
+               if (iscntrl((unsigned char) *p))
+                       fputc('?', stdout);
+               else
+                       fputc(*p, stdout);
+       }
+}
+
 static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
 {
        struct libmnt_table *tb;
@@ -157,7 +174,9 @@ static void print_all(struct libmnt_context *cxt, char *pattern, int show_label)
 
                if (!mnt_fs_is_pseudofs(fs))
                        xsrc = mnt_pretty_path(src, cache);
-               printf ("%s on %s", xsrc ? xsrc : src, mnt_fs_get_target(fs));
+               printf ("%s on ", xsrc ? xsrc : src);
+               safe_fputs(mnt_fs_get_target(fs));
+
                if (type)
                        printf (" type %s", type);
                if (optstr)