Date: Fri, 18 Feb 2005 15:30:45 -0500 From: Craig Rodrigues <rodrigc@crodrigues.org> To: freebsd-gnats-submit@freebsd.org Cc: freebsd-standards@freebsd.org Subject: Re: threads/76938: include/unistd.h: ttyname_r prototype missing Message-ID: <20050218203045.GA12436@crodrigues.org>
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The following patch exports ttyname_r() from <unistd.h> and makes it conform to the Single Unix Specification: http://www.opengroup.org/onlinepubs/009695399/functions/ttyname.html Can someone with a commit bit take a look at it? -- Craig Rodrigues rodrigc@crodrigues.org --- lib/libc/gen/ttyname.3.orig Thu Feb 17 17:10:20 2005 +++ lib/libc/gen/ttyname.3 Fri Feb 18 15:10:31 2005 @@ -37,6 +37,7 @@ .Os .Sh NAME .Nm ttyname , +.Nm ttyname_r , .Nm isatty , .Nm ttyslot .Nd get name of associated terminal (tty) from file descriptor @@ -47,6 +48,8 @@ .Ft char * .Fn ttyname "int fd" .Ft int +.Fn ttyname_r "int fd" "char *buf" "size_t bufsize" +.Ft int .Fn isatty "int fd" .Ft int .Fn ttyslot void @@ -80,7 +83,13 @@ gets the related device name of a file descriptor for which .Fn isatty -is true +is true. +.Pp +.Fn ttyname +returns the name stored in a static buffer which will be overwritten +on subsequent calls. +.Fn ttyname_r +takes a buffer and length as arguments to avoid this problem. .Pp The .Fn ttyslot @@ -98,12 +107,25 @@ a .Dv NULL pointer is returned. +The +.Fn ttyname_r +function returns 0 if successful. Otherwise an error number is returned. .Pp The .Fn ttyslot function returns the unit number of the device file if found; otherwise the value zero is returned. +.Sh ERRORS +.Fn ttyname_r +may return the following error codes: +.Bl -tag -width Er +.It Bq Er ENOTTY +.Fa fd +is not a valid file descriptor. +.It Bq Er ERANGE +.Fa bufsize +is smaller than the length of the string to be returned. .Sh FILES .Bl -tag -width /etc/ttys -compact .It Pa /dev/\(** @@ -121,11 +143,6 @@ function appeared in .At v7 . -.Sh BUGS -The -.Fn ttyname -function leaves its result in an internal static object and returns -a pointer to that object. -Subsequent calls to -.Fn ttyname -will modify the same object. +.Fn ttyname_r +appeared in +.Fx 6.0 . --- lib/libc/gen/ttyname.c.orig Thu Feb 17 17:14:32 2005 +++ lib/libc/gen/ttyname.c Fri Feb 18 15:20:09 2005 @@ -48,12 +48,13 @@ #include <string.h> #include <paths.h> #include <pthread.h> +#include <errno.h> #include "un-namespace.h" #include "libc_private.h" static char buf[sizeof(_PATH_DEV) + MAXNAMLEN]; -static char *ttyname_threaded(int fd); +static void ttyname_threaded(int fd, char **b); static char *ttyname_unthreaded(int fd); static pthread_mutex_t ttyname_lock = PTHREAD_MUTEX_INITIALIZER; @@ -68,45 +69,41 @@ if (__isthreaded == 0) ret = ttyname_unthreaded(fd); else - ret = ttyname_threaded(fd); + ttyname_threaded(fd, &ret); return (ret); } -char * +int ttyname_r(int fd, char *buf, size_t len) { struct stat sb; - char *rval; - - rval = NULL; /* Must be a terminal. */ if (!isatty(fd)) - return (rval); + return ENOTTY; /* Must be a character device. */ if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) - return (rval); + return ENOTTY; /* Must have enough room */ if (len <= sizeof(_PATH_DEV)) - return (rval); + return ERANGE; strcpy(buf, _PATH_DEV); devname_r(sb.st_rdev, S_IFCHR, - buf + strlen(buf), sizeof(buf) - strlen(buf)); - return (buf); + buf + strlen(buf), len - strlen(buf)); + return 0; } -static char * -ttyname_threaded(int fd) +static void +ttyname_threaded(int fd, char **b) { - char *buf; - if (ttyname_init == 0) { _pthread_mutex_lock(&ttyname_lock); if (ttyname_init == 0) { if (_pthread_key_create(&ttyname_key, free)) { _pthread_mutex_unlock(&ttyname_lock); - return (NULL); + *b = NULL; + return; } ttyname_init = 1; } @@ -114,17 +111,19 @@ } /* Must have thread specific data field to put data */ - if ((buf = _pthread_getspecific(ttyname_key)) == NULL) { - if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) { - if (_pthread_setspecific(ttyname_key, buf) != 0) { - free(buf); - return (NULL); + if ((*b = _pthread_getspecific(ttyname_key)) == NULL) { + if ((*b = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) { + if (_pthread_setspecific(ttyname_key, *b) != 0) { + free(*b); + *b = NULL; + return; } } else { - return (NULL); + *b = NULL; + return; } } - return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN)); + ttyname_r(fd, *b, sizeof(_PATH_DEV) + MAXNAMLEN); } static char * --- include/unistd.h.orig Thu Feb 17 17:37:41 2005 +++ include/unistd.h Thu Feb 17 17:38:19 2005 @@ -365,6 +365,7 @@ pid_t tcgetpgrp(int); int tcsetpgrp(int, pid_t); char *ttyname(int); +int ttyname_r(int, char *, size_t); int unlink(const char *); ssize_t write(int, const void *, size_t);
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