From f2f170ddd8d54aa95c75879e4e329feaf19ef119 Mon Sep 17 00:00:00 2001 From: ngie Date: Tue, 1 Dec 2015 18:19:23 +0000 Subject: [PATCH] MFC r285140: r285140 (by oshogbo): Add fdclose(3) function. This function is equivalent to fclose(3) function except that it does not close the underlying file descriptor. fdclose(3) is step forward to make FILE structure private. Reviewed by: wblock, jilles, jhb, pjd Approved by: pjd (mentor) Differential Revision: https://reviews.freebsd.org/D2697 --- include/stdio.h | 1 + lib/libc/stdio/Symbol.map | 4 ++ lib/libc/stdio/fclose.3 | 82 +++++++++++++++++++++++++++++++-------- lib/libc/stdio/fclose.c | 77 ++++++++++++++++++++++++++++++------ 4 files changed, 136 insertions(+), 28 deletions(-) diff --git a/include/stdio.h b/include/stdio.h index d37ea06d925e..5d3e5a2aee0a 100644 --- a/include/stdio.h +++ b/include/stdio.h @@ -399,6 +399,7 @@ int (dprintf)(int, const char * __restrict, ...); int asprintf(char **, const char *, ...) __printflike(2, 3); char *ctermid_r(char *); void fcloseall(void); +int fdclose(FILE *, int *); char *fgetln(FILE *, size_t *); const char *fmtcheck(const char *, const char *) __format_arg(2); int fpurge(FILE *); diff --git a/lib/libc/stdio/Symbol.map b/lib/libc/stdio/Symbol.map index d2a8c92b2411..a332ab26d3c0 100644 --- a/lib/libc/stdio/Symbol.map +++ b/lib/libc/stdio/Symbol.map @@ -162,6 +162,10 @@ FBSD_1.3 { mkostemps; }; +FBSD_1.4 { + fdclose; +}; + FBSDprivate_1.0 { _flockfile; _flockfile_debug_stub; diff --git a/lib/libc/stdio/fclose.3 b/lib/libc/stdio/fclose.3 index 883aa108e7db..596ee3db0e6b 100644 --- a/lib/libc/stdio/fclose.3 +++ b/lib/libc/stdio/fclose.3 @@ -1,5 +1,6 @@ -.\" Copyright (c) 1990, 1991, 1993 -.\" The Regents of the University of California. All rights reserved. +.\" Copyright (c) 1990, 1991, 1993 The Regents of the University of California. +.\" Copyright (c) 2015 Mariusz Zaborski +.\" All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" Chris Torek and the American National Standards Committee X3, @@ -32,11 +33,12 @@ .\" @(#)fclose.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd April 22, 2006 +.Dd July 4, 2015 .Dt FCLOSE 3 .Os .Sh NAME .Nm fclose , +.Nm fdclose , .Nm fcloseall .Nd close a stream .Sh LIBRARY @@ -45,6 +47,8 @@ .In stdio.h .Ft int .Fn fclose "FILE *stream" +.Ft int +.Fn fdclose "FILE *stream" "int *fdp" .Ft void .Fn fcloseall void .Sh DESCRIPTION @@ -59,36 +63,77 @@ first, using .Xr fflush 3 . .Pp The +.Fn fdclose +function is equivalent to +.Fn fclose +except that it does not close the underlying file descriptor. +If +.Fa fdp +is not +.Dv NULL , +the file descriptor will be written to it. +If the +.Fa fdp +argument will be different then NULL the file descriptor will be returned in it, +If the stream does not have an associated file descriptor, +.Fa fdp +will be set to -1. +This type of stream is created with functions such as +.Xr fmemopen 3 , +.Xr funopen 3 , +or +.Xr open_memstream 3 . +.Pp +The .Fn fcloseall function calls .Fn fclose on all open streams. .Sh RETURN VALUES -Upon successful completion 0 is returned. +.Fn fcloseall +does not return a value. +.Pp +Upon successful completion the +.Fn fclose +and +.Fn fdclose +functions return 0. Otherwise, .Dv EOF is returned and the global variable .Va errno is set to indicate the error. -In either case no further access to the stream is possible. .Sh ERRORS +.Fn fdclose +fails if: +.Bl -tag -width Er +.It Bq Er EOPNOTSUPP +The stream does not have an associated file descriptor. +.El +.Pp The .Fn fclose -function -may also fail and set +and +.Fn fdclose +functions may also fail and set .Va errno -for any of the errors specified for the routines -.Xr close 2 -or +for any of the errors specified for .Xr fflush 3 . +.Pp +The +.Fn fclose +function may also fail and set errno for any of the errors specified for +.Xr close 2 . .Sh NOTES The .Fn fclose -function -does not handle NULL arguments; they will result in a segmentation -violation. -This is intentional - it makes it easier to make sure programs written -under +and +.Fn fdclose +functions do not handle NULL arguments in the +.Fa stream +variable; this will result in a segmentation violation. +This is intentional. +It makes it easier to make sure programs written under .Fx are bug free. This behaviour is an implementation detail, and programs should not @@ -104,8 +149,13 @@ The function conforms to .St -isoC . -.Pp +.Sh HISTORY The .Fn fcloseall function first appeared in .Fx 7.0 . +.Pp +The +.Fn fdclose +function first appeared in +.Fx 11.0 . diff --git a/lib/libc/stdio/fclose.c b/lib/libc/stdio/fclose.c index 5ed8b2c548f6..24b9b90af985 100644 --- a/lib/libc/stdio/fclose.c +++ b/lib/libc/stdio/fclose.c @@ -1,6 +1,7 @@ /*- - * Copyright (c) 1990, 1993 - * The Regents of the University of California. All rights reserved. + * Copyright (c) 1990, 1993 The Regents of the University of California. + * Copyright (c) 2013 Mariusz Zaborski + * All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. @@ -38,6 +39,7 @@ __FBSDID("$FreeBSD$"); #include "namespace.h" #include +#include #include #include #include "un-namespace.h" @@ -45,19 +47,17 @@ __FBSDID("$FreeBSD$"); #include "libc_private.h" #include "local.h" -int -fclose(FILE *fp) +static int +cleanfile(FILE *fp, bool c) { int r; - if (fp->_flags == 0) { /* not open! */ - errno = EBADF; - return (EOF); - } - FLOCKFILE(fp); r = fp->_flags & __SWR ? __sflush(fp) : 0; - if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0) - r = EOF; + if (c) { + if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0) + r = EOF; + } + if (fp->_flags & __SMBF) free((char *)fp->_bf._base); if (HASUB(fp)) @@ -80,6 +80,59 @@ fclose(FILE *fp) STDIO_THREAD_LOCK(); fp->_flags = 0; /* Release this FILE for reuse. */ STDIO_THREAD_UNLOCK(); - FUNLOCKFILE(fp); + + return (r); +} + +int +fdclose(FILE *fp, int *fdp) +{ + int r, err; + + if (fdp != NULL) + *fdp = -1; + + if (fp->_flags == 0) { /* not open! */ + errno = EBADF; + return (EOF); + } + + FLOCKFILE(fp); + r = 0; + if (fp->_close != __sclose) { + r = EOF; + errno = EOPNOTSUPP; + } else if (fp->_file < 0) { + r = EOF; + errno = EBADF; + } + if (r == EOF) { + err = errno; + (void)cleanfile(fp, true); + errno = err; + } else { + if (fdp != NULL) + *fdp = fp->_file; + r = cleanfile(fp, false); + } + FUNLOCKFILE(fp); + + return (r); +} + +int +fclose(FILE *fp) +{ + int r; + + if (fp->_flags == 0) { /* not open! */ + errno = EBADF; + return (EOF); + } + + FLOCKFILE(fp); + r = cleanfile(fp, true); + FUNLOCKFILE(fp); + return (r); }