From 1dba3c20aa95bcb3b77db21285b99ac3baf21d7c Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Mon, 4 Apr 2005 13:10:49 +0000 Subject: [PATCH] Patch from AEB: improved DESCRIPTION; clarified distinction between EACCES and ENOEXEC. --- man2/uselib.2 | 46 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 36 insertions(+), 10 deletions(-) diff --git a/man2/uselib.2 b/man2/uselib.2 index 92cf69bef..80e02c21d 100644 --- a/man2/uselib.2 +++ b/man2/uselib.2 @@ -10,7 +10,7 @@ .\" manual under the conditions for verbatim copying, provided that the .\" entire resulting derived work is distributed under the terms of a .\" permission notice identical to this one. -.\" +.\" .\" Since the Linux kernel and libraries are constantly changing, this .\" manual page may be incorrect or out-of-date. The author(s) assume no .\" responsibility for errors or omissions, or for damages resulting from @@ -18,25 +18,29 @@ .\" have taken the same level of care in the production of this manual, .\" which is licensed free of charge, as they might when working .\" professionally. -.\" +.\" .\" Formatted or processed versions of this manual, if unaccompanied by .\" the source, must acknowledge the copyright and authors of this work. .\" .\" Modified by Michael Haardt .\" Modified 1993-07-24 by Rik Faith .\" Modified 1996-10-22 by Eric S. Raymond -.\" Modified 2004-06-23 by Michael Kerrisk +.\" Modified 2004-06-23 by Michael Kerrisk +.\" Modified 2005-01-09 by aeb .\" -.TH USELIB 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual" +.TH USELIB 2 2005-01-09 "Linux 2.6.10" "Linux Programmer's Manual" .SH NAME -uselib \- select shared library +uselib \- load shared library .SH SYNOPSIS .B #include .sp .BI "int uselib(const char *" library ); .SH DESCRIPTION -\fBuselib\fP selects the shared library binary that will be used by -the calling process. +The system call \fBuselib\fP serves to load +a shared library to be used by the calling process. +It is given a pathname. The address where to load is found +in the library itself. The library can have any recognized +binary format. .SH "RETURN VALUE" On success, zero is returned. On error, \-1 is returned, and .I errno @@ -52,8 +56,9 @@ the following may also be returned: .B EACCES The library specified by .I library -is not readable, or the caller does not have search permission -for one of the directories in the path prefix. (See also +does not have read or execute permission, or the caller does not have +search permission for one of the directories in the path prefix. +(See also .BR path_resolution (2).) .TP .B ENFILE @@ -62,10 +67,30 @@ The system limit on the total number of open files has been reached. .B ENOEXEC The file specified by .I library -is not executable, or does not have the correct magic numbers. +is not an executable of known type, +e.g., does not have the correct magic numbers. .SH "CONFORMING TO" \fBuselib()\fP is Linux specific, and should not be used in programs intended to be portable. +.SH NOTES +\fBuselib()\fP was used by early libc startup code to load +the shared libraries with names found in an array of names +in the binary. +.LP +.\" libc 4.3.1f - changelog 1993-03-02 +Since libc 4.3.2, startup code tries to prefix these names +with "/usr/lib", "/lib" and "" before giving up. +.\" libc 4.3.4 - changelog 1993-04-21 +In libc 4.3.4 and later these names are looked for in the directories +found in LD_LIBRARY_PATH, and if not found there, +prefixes "/usr/lib", "/lib" and "/" are tried. +.LP +From libc 4.4.4 on only the library "/lib/ld.so" is loaded, +so that this dynamic library can load the remaining libraries needed +(again using this call). +This is also the state of affairs in libc5. +.LP +glibc2 does not use this call. .SH "SEE ALSO" .BR ar (1), .BR gcc (1), @@ -73,5 +98,6 @@ intended to be portable. .BR ldd (1), .BR mmap (2), .BR open (2), +.BR dlopen (3), .BR capability (7), .BR ld.so (8)