mktemp: add support for -u

zlib-1.2.6 Makefile uses "mktemp -u".

function                                             old     new   delta
___path_search                                         -     266    +266
mktemp_main                                          165     250     +85
tempnam                                                -      79     +79
packed_usage                                       29189   29176     -13
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 1/1 up/down: 430/-13)           Total: 417 bytes

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

1 files changed, 20 insertions, 3 deletions

diff --git a/debianutils/mktemp.c b/debianutils/mktemp.c
index 007cb1c5b..dbe430955 100644
--- a/debianutils/mktemp.c
+++ b/debianutils/mktemp.c
@@ -41,6 +41,7 @@
 ////usage:   "\n        -q      Fail silently on errors" - we ignore this opt
 //usage:     "\n        -t      Prepend base directory name to TEMPLATE"
 //usage:     "\n        -p DIR  Use DIR as a base directory (implies -t)"
+//usage:     "\n        -u      Do not create anything; print a name"
 //usage:     "\n"
 //usage:     "\nBase directory is: -p DIR, else $TMPDIR, else /tmp"
 //usage:
@@ -63,6 +64,7 @@ int mktemp_main(int argc UNUSED_PARAM, char **argv)
                 OPT_q = 1 << 1,
                 OPT_t = 1 << 2,
                 OPT_p = 1 << 3,
+                OPT_u = 1 << 4,
         };
 
         path = getenv("TMPDIR");
@@ -71,7 +73,7 @@ int mktemp_main(int argc UNUSED_PARAM, char **argv)
 
         /* -q is ignored */
         opt_complementary = "?1"; /* 1 argument max */
-        opts = getopt32(argv, "dqtp:", &path);
+        opts = getopt32(argv, "dqtp:u", &path);
 
         chp = argv[optind];
         if (!chp) {
@@ -81,6 +83,22 @@ int mktemp_main(int argc UNUSED_PARAM, char **argv)
                 chp = xstrdup("tmp.XXXXXX");
                 opts |= OPT_t;
         }
+
+        if (opts & OPT_u) {
+                /* Remove (up to) 6 X's */
+                unsigned len = strlen(chp);
+                int cnt = len > 6 ? 6 : len;
+                while (--cnt >= 0 && chp[--len] == 'X')
+                        chp[len] = '\0';
+
+                chp = tempnam(opts & (OPT_t|OPT_p) ? path : "./", chp);
+                if (!chp)
+                        return EXIT_FAILURE;
+                if (!(opts & (OPT_t|OPT_p)))
+                        chp += 2;
+                goto ret;
+        }
+
         if (opts & (OPT_t|OPT_p))
                 chp = concat_path_file(path, chp);
 
@@ -91,8 +109,7 @@ int mktemp_main(int argc UNUSED_PARAM, char **argv)
                 if (mkstemp(chp) < 0)
                         return EXIT_FAILURE;
         }
-
+ ret:
         puts(chp);
-
         return EXIT_SUCCESS;
 }