diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | manual/job.texi | 8 | ||||
| -rw-r--r-- | sysdeps/posix/ctermid.c | 16 |
3 files changed, 21 insertions, 11 deletions
@@ -1,5 +1,13 @@ 2014-11-21 Alexandre Oliva <aoliva@redhat.com> + * sysdeps/posix/ctermid.c (ctermid): Return a pointer to a + string literal if not passed a buffer. + * manual/job.texi (ctermid): Update reasoning, note deviation + from posix, suggest mtasurace when not passed a buffer, for + future non-preliminary safety notes. + +2014-11-21 Alexandre Oliva <aoliva@redhat.com> + * manual/users.texi (cuserid): Fix MT-Safety note for the case of not passing it a buffer. Reported by Peng Haitao. diff --git a/manual/job.texi b/manual/job.texi index 4f9bd81ffe..095c26d930 100644 --- a/manual/job.texi +++ b/manual/job.texi @@ -1039,10 +1039,12 @@ The function @code{ctermid} is declared in the header file @comment stdio.h @comment POSIX.1 @deftypefun {char *} ctermid (char *@var{string}) -@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} +@safety{@prelim{}@mtsafe{@mtsposix{/!string}}@assafe{}@acsafe{}} @c This function is a stub by default; the actual implementation, for -@c posix systems, returns an internal buffer if passed a NULL string, -@c but the internal buffer is always set to /dev/tty. +@c posix systems, returns a pointer to a string literal if passed a NULL +@c string. It's not clear we want to commit to being MT-Safe in the +@c !string case, so maybe add mtasurace{:ctermid/!string} when we take +@c prelim out, to make room for using a static buffer in the future. The @code{ctermid} function returns a string containing the file name of the controlling terminal for the current process. If @var{string} is not a null pointer, it should be an array that can hold at least diff --git a/sysdeps/posix/ctermid.c b/sysdeps/posix/ctermid.c index 0ef9a3fe23..9714285224 100644 --- a/sysdeps/posix/ctermid.c +++ b/sysdeps/posix/ctermid.c @@ -19,17 +19,17 @@ #include <string.h> -/* Return the name of the controlling terminal. - If S is not NULL, the name is copied into it (it should be at - least L_ctermid bytes long), otherwise a static buffer is used. */ +/* Return the name of the controlling terminal. If S is not NULL, the + name is copied into it (it should be at least L_ctermid bytes + long), otherwise we return a pointer to a non-const but read-only + string literal, that POSIX states the caller must not modify. */ char * -ctermid (s) - char *s; +ctermid (char *s) { - static char name[L_ctermid]; + char *name = (char /*drop const*/ *) "/dev/tty"; if (s == NULL) - s = name; + return name; - return strcpy (s, "/dev/tty"); + return strcpy (s, name); } |