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authorUlrich Drepper <drepper@redhat.com>1996-09-28 03:24:10 +0000
committerUlrich Drepper <drepper@redhat.com>1996-09-28 03:24:10 +0000
commitd68171edce96cb59b5cb869f6a82afcc50db00be (patch)
treef149db9027e600965c482e090c29bd058eea3454 /manual/filesys.texi
parentc40298232a7ed3fb1b64eb4ffe352829deb79694 (diff)
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update from main archive 960927cvs/libc-961001cvs/libc-960929cvs/libc-960928
Sat Sep 28 03:02:49 1996 Ulrich Drepper <drepper@cygnus.com> * dirent/Makefile (routines): Add readdir_r. * dirent/readdir_r.c: New file. Wrapper around readdir.c. * dirent/dirent.h: Add prototype for readdir_r. * misc/hsearch_r.c (ENTRY): Make field `used' of type `unsigned int' to prevent warnings. * sysdeps/unix/sysv/linux/getsysstats.c (get_proc_path): Initialize `result'. Sat Sep 28 01:16:42 1996 Ulrich Drepper <drepper@cygnus.com> * sysdeps/generic/strsep.c: Rename to __strsep and make strsep weak alias. * string/string.h: Add prototype for __strsep. * misc/mntent_r.c: Use __strsep instead of strsep to keep namespace clean. * sysdeps/stub/nanosleep.c: Rename to __libc_nanosleep and make __nanosleep and nanosleep weak aliases. * sysdeps/unix/sysv/linux/syscalls.list: Add __nanosleep as weak alias. * sysdeps/unix/sysv/linux/sleep.c: Call __nanosleep instead of nanosleep to keep namespace clean. * sysdeps/posix/ttyname.c (ttyname): Add cast to prevent warning. * sysdeps/posix/ttyname_r.c (ttyname_r): Likewise. * sysdeps/posix/getcwd.c (__getcwd): Likewise. * sysdeps/unix/nlist.c: Use ISO C definition since we don't always have prototype. * login/Makefile (headers): Add pty.h. * login/pty.h: New file. * sysdeps/generic/pty.h: Include <pty.h>. * login/pututline_r.c: Add cast to prevent warning. * gmon/gmon.c: Add prototype for __profile_frequency. (monstartup): Add cast to prevent warning. * sysdeps/generic/prof-freq.c: Change to use ISO C style definition. * locale/programs/ld-time.c (time_output): Write `era' information in correct order. Sat Sep 28 00:11:08 1996 Ulrich Drepper <drepper@cygnus.com> * sysdeps/unix/sysv/linux/syscalls.list: Add weak alias `adjtimex'. Set caller for mlock, mlockall, mremap, munlock, and munlockall to EXTRA. Reported by Matthias Urlichs <smurf@smurf.noris.de>. 1996-09-27 Paul Eggert <eggert@twinsun.com> * strftime.c (strftime): Output incomplete formats like %E at end of string. 1996-09-27 Paul Eggert <eggert@twinsun.com> * strftime.c (strftime): Add support for %EC and %Ey. Fix support for %EY. This uses the new _nl_get_era_entry function. Fri Sep 27 14:12:27 1996 Ulrich Drepper <drepper@cygnus.com> Security related patch by Elliot Lee <sopwith@redhat.com> and David Holland <dholland@eecs.harvard.edu>. * inet/rexec.c (rexec): Increase size of `num' array from 8 to 32. * inet/ruserpass.c (ruserpass): Don't allow $HOME envvar to not exist. * sysdeps/generic/getenv.c (__secure_getenv): New function. Return NULL when programs runs with SUID or SGID enabled. * sysdeps/stub/getenv.c: Make __secure_getenv an alias of getenv. * stdlib/stdlib.h: Add prototype for __secure_getenv. * locale/setlocale.c: Use __secure_getenv. * resolv/res_init.c: Likewise. * resolv/res_query.c: Likewise. * inet/ruserpass.c: Likewise. * sysdeps/posix/tempname.c: Likewise. * malloc/mtrace.c: Likewise. * catgets/catgets.c: Likewise. Make temporary file handling functions reentrant. * stdio-common/tmpnam.c: Rewrite to have own buffer to write result to. The called __stdio_gen_tempname function must be thread safe. * stdio-common/tmpnam_r.c: New file. * stdio/stdio.h: Add prototype for `tmpnam_r'. Change prototype for __stdio_gen_tempname. * stdio/libio.h: Likewise. * sysdeps/posix/tempname.c: Add new parameters and use them instead of static buffer. Don't reset `indeces' when PID changed between calls. Don't fail for long running programs when index counter once reached the limit. * sysdeps/stub/tempname.c: Likewise. * stdio-common/tempnam.c: Provide local buffer as extra argument to __stdio_gen_tempname. This makes this function reentrant. * stdio-common/tmpfile.c: Likewise. * stdio-common/temptest.c: Provide extra argument to __stdio_gen_tempname. * manual/filesys.texi: Describe tmpnam_r and add comments about reentrancy of the functions. * inet/rcmd.c: Fixed address length handling. * sysdeps/posix/mk-stdiolim.c: Count final \0 byte in L_tmpnam value. * time/strftime.c: Remove unused variables alt_digits and end_alt_digits. * sysdeps/unix/sysv/linux/sys/sysinfo.h: Correct prototype names for get_nprocs and get_nprocs_conf. * sysdeps/generic/sys/sysinfo.h: Likewise. * stdlib/test-canon.c: Finally do the right fix. * misc/Makefile: Only compile force-wrapper when compiling reentrant libc.
Diffstat (limited to 'manual/filesys.texi')
-rw-r--r--manual/filesys.texi77
1 files changed, 48 insertions, 29 deletions
diff --git a/manual/filesys.texi b/manual/filesys.texi
index d2afe8623f..e269663e70 100644
--- a/manual/filesys.texi
+++ b/manual/filesys.texi
@@ -261,7 +261,7 @@ are declared in the header file @file{dirent.h}.
@comment dirent.h
@comment POSIX.1
@deftp {Data Type} DIR
-The @code{DIR} data type represents a directory stream.
+The @code{DIR} data type represents a directory stream.
@end deftp
You shouldn't ever allocate objects of the @code{struct dirent} or
@@ -333,7 +333,7 @@ The @var{dirstream} argument is not valid.
@comment POSIX.1
@deftypefun int closedir (DIR *@var{dirstream})
This function closes the directory stream @var{dirstream}. It returns
-@code{0} on success and @code{-1} on failure.
+@code{0} on success and @code{-1} on failure.
The following @code{errno} error conditions are defined for this
function:
@@ -443,7 +443,7 @@ following @code{errno} error conditions are defined for this function:
@item EACCES
You are not allowed to write the directory in which the new link is to
be written.
-@ignore
+@ignore
Some implementations also require that the existing file be accessible
by the caller, and use this error to report failure for that reason.
@end ignore
@@ -627,7 +627,7 @@ The function @code{unlink} is declared in the header file @file{unistd.h}.
This function returns @code{0} on successful completion, and @code{-1}
on error. In addition to the usual file name errors
-(@pxref{File Name Errors}), the following @code{errno} error conditions are
+(@pxref{File Name Errors}), the following @code{errno} error conditions are
defined for this function:
@table @code
@@ -672,7 +672,7 @@ are two additional @code{errno} error conditions defined for
@table @code
@item ENOTEMPTY
@itemx EEXIST
-The directory to be deleted is not empty.
+The directory to be deleted is not empty.
@end table
These two error codes are synonymous; some systems use one, and some use
@@ -851,20 +851,20 @@ This section contains information about how you can inquire about and
modify these attributes of files.
@menu
-* Attribute Meanings:: The names of the file attributes,
+* Attribute Meanings:: The names of the file attributes,
and what their values mean.
* Reading Attributes:: How to read the attributes of a file.
* Testing File Type:: Distinguishing ordinary files,
- directories, links...
+ directories, links...
* File Owner:: How ownership for new files is determined,
and how to change it.
* Permission Bits:: How information about a file's access
- mode is stored.
+ mode is stored.
* Access Permission:: How the system decides who can access a file.
* Setting Permissions:: How permissions for new files are assigned,
and how to change them.
* Testing File Access:: How to find out if your process can
- access a file.
+ access a file.
* File Times:: About the time attributes of a file.
@end menu
@@ -1079,7 +1079,7 @@ a socket, and so on. For information about the access permission,
@ref{Permission Bits}.
There are two predefined ways you can access the file type portion of
-the file mode. First of all, for each type of file, there is a
+the file mode. First of all, for each type of file, there is a
@dfn{predicate macro} which examines a file mode value and returns
true or false---is the file of that type, or not. Secondly, you can
mask out the rest of the file mode to get just a file type code.
@@ -1260,7 +1260,7 @@ bits may not be appropriate for the new owner.) The other file
permission bits are not changed.
The return value is @code{0} on success and @code{-1} on failure.
-In addition to the usual file name errors (@pxref{File Name Errors}),
+In addition to the usual file name errors (@pxref{File Name Errors}),
the following @code{errno} error conditions are defined for this function:
@table @code
@@ -1421,7 +1421,7 @@ This is equivalent to @samp{(S_IROTH | S_IWOTH | S_IXOTH)}.
@comment POSIX
@item S_ISUID
@vindex S_ISUID
-This is the set-user-ID on execute bit, usually 04000.
+This is the set-user-ID on execute bit, usually 04000.
@xref{How Change Persona}.
@comment sys/stat.h
@@ -1462,7 +1462,7 @@ arose since the last run.
On some modern systems where the sticky bit has no useful meaning for an
executable file, you cannot set the bit at all for a non-directory.
-If you try, @code{chmod} fails with @code{EFTYPE};
+If you try, @code{chmod} fails with @code{EFTYPE};
@pxref{Setting Permissions}.
Some systems (particularly SunOS) have yet another use for the sticky
@@ -1527,7 +1527,7 @@ The bits that are set in the file creation mask identify permissions
that are always to be disabled for newly created files. For example, if
you set all the ``other'' access bits in the mask, then newly created
files are not accessible at all to processes in the ``other''
-category, even if the @var{mode} argument specified to the creation
+category, even if the @var{mode} argument specified to the creation
function would permit such access. In other words, the file creation
mask is the complement of the ordinary access permissions you want to
grant.
@@ -1671,7 +1671,7 @@ files off-limits to ordinary users---for example, to modify
@file{/etc/passwd}. Programs designed to be run by ordinary users but
access such files use the setuid bit feature so that they always run
with @code{root} as the effective user ID.
-
+
Such a program may also access files specified by the user, files which
conceptually are being accessed explicitly by the user. Since the
program runs as @code{root}, it has permission to access whatever file
@@ -1776,7 +1776,7 @@ Argument that means, test for existence of the file.
Each file has three timestamps associated with it: its access time,
its modification time, and its attribute modification time. These
correspond to the @code{st_atime}, @code{st_mtime}, and @code{st_ctime}
-members of the @code{stat} structure; see @ref{File Attributes}.
+members of the @code{stat} structure; see @ref{File Attributes}.
All of these times are represented in calendar time format, as
@code{time_t} objects. This data type is defined in @file{time.h}.
@@ -1832,7 +1832,7 @@ named @var{filename}.
If @var{times} is a null pointer, then the access and modification times
of the file are set to the current time. Otherwise, they are set to the
values from the @code{actime} and @code{modtime} members (respectively)
-of the @code{utimbuf} structure pointed at by @var{times}.
+of the @code{utimbuf} structure pointed at by @var{times}.
The attribute modification time for the file is set to the current time
in either case (since changing the timestamps is itself a modification
@@ -1938,12 +1938,14 @@ this file, you must remove the old file explicitly first.
If you need to use a temporary file in your program, you can use the
@code{tmpfile} function to open it. Or you can use the @code{tmpnam}
-function make a name for a temporary file and then open it in the usual
-way with @code{fopen}.
+(better: @code{tmpnam_r}) function make a name for a temporary file and
+then open it in the usual way with @code{fopen}.
The @code{tempnam} function is like @code{tmpnam} but lets you choose
what directory temporary files will go in, and something about what
-their file names will look like.
+their file names will look like. Important for multi threaded programs
+is that @code{tempnam} is reentrant while @code{tmpnam} is not since it
+returns a pointer to a static buffer.
These facilities are declared in the header file @file{stdio.h}.
@pindex stdio.h
@@ -1956,6 +1958,8 @@ calling @code{fopen} with mode @code{"wb+"}. The file is deleted
automatically when it is closed or when the program terminates. (On
some other ANSI C systems the file may fail to be deleted if the program
terminates abnormally).
+
+This function is reentrant.
@end deftypefun
@comment stdio.h
@@ -1964,14 +1968,26 @@ terminates abnormally).
This function constructs and returns a file name that is a valid file
name and that does not name any existing file. If the @var{result}
argument is a null pointer, the return value is a pointer to an internal
-static string, which might be modified by subsequent calls. Otherwise,
-the @var{result} argument should be a pointer to an array of at least
-@code{L_tmpnam} characters, and the result is written into that array.
-
-It is possible for @code{tmpnam} to fail if you call it too many times.
-This is because the fixed length of a temporary file name gives room for
-only a finite number of different names. If @code{tmpnam} fails, it
-returns a null pointer.
+static string, which might be modified by subsequent calls and therefore
+makes this function non-reentrant. Otherwise, the @var{result} argument
+should be a pointer to an array of at least @code{L_tmpnam} characters,
+and the result is written into that array.
+
+It is possible for @code{tmpnam} to fail if you call it too many times
+without removing previously created files. This is because the fixed
+length of a temporary file name gives room for only a finite number of
+different names. If @code{tmpnam} fails, it returns a null pointer.
+@end deftypefun
+
+@comment stdio.h
+@comment GNU
+@deftypefun {char *} tmpnam_r (char *@var{result})
+This function is nearly identical to the @code{tmpnam} function. But it
+does not allow @var{result} to be a null pointer. In the later case a
+null pointer is returned.
+
+This function is reentrant because the non-reentrant situation of
+@code{tmpnam} cannot happen here.
@end deftypefun
@comment stdio.h
@@ -2006,13 +2022,16 @@ prefix for the file name. The return value is a string newly allocated
with @code{malloc}; you should release its storage with @code{free} when
it is no longer needed.
+Because the string is dynamically allocated this function is reentrant.
+
The directory prefix for the temporary file name is determined by testing
each of the following, in sequence. The directory must exist and be
writable.
@itemize @bullet
@item
-The environment variable @code{TMPDIR}, if it is defined.
+The environment variable @code{TMPDIR}, if it is defined. For security
+reasons this only happens if the program is not SUID or SGID enabled.
@item
The @var{dir} argument, if it is not a null pointer.