Mercurial > hg > octave-lyh > gnulib-hg
changeset 5938:14697da96543
2005-06-28 Simon Josefsson <jas@extundo.com>
* gnulib.texi (Library version handling): New section.
author | Simon Josefsson <simon@josefsson.org> |
---|---|
date | Mon, 27 Jun 2005 22:36:50 +0000 |
parents | 5e8346b0cc53 |
children | 7e7ddabe954a |
files | doc/ChangeLog doc/gnulib.texi |
diffstat | 2 files changed, 52 insertions(+), 2 deletions(-) [+] |
line wrap: on
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--- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,3 +1,7 @@ +2005-06-28 Simon Josefsson <jas@extundo.com> + + * gnulib.texi (Library version handling): New section. + 2005-05-11 Paul Eggert <eggert@cs.ucla.edu> * getdate.texi (General date syntax): Don't say that date
--- a/doc/gnulib.texi +++ b/doc/gnulib.texi @@ -1,5 +1,5 @@ \input texinfo @c -*-texinfo-*- -@comment $Id: gnulib.texi,v 1.9 2005-05-23 11:05:53 jas Exp $ +@comment $Id: gnulib.texi,v 1.10 2005-06-27 22:36:50 jas Exp $ @comment %**start of header @setfilename gnulib.info @settitle GNU Gnulib @@ -7,7 +7,7 @@ @syncodeindex pg cp @comment %**end of header -@set UPDATED $Date: 2005-05-23 11:05:53 $ +@set UPDATED $Date: 2005-06-27 22:36:50 $ @copying This manual is for GNU Gnulib (updated @value{UPDATED}), @@ -85,6 +85,7 @@ * ctime:: * inet_ntoa:: * Out of memory handling:: +* Library version handling:: @end menu @node Comments @@ -251,6 +252,51 @@ fail. +@node Library version handling +@section Library version handling + +The module ``check_version'' can be useful when your gnulib +application is a system library. You will typically wrap the call to +the @code{check_version} function through a library API, your library +header file may contain: + +@example +#define STRINGPREP_VERSION "0.5.18" +... + extern const char *stringprep_check_version (const char *req_version); +@end example + +The implementation of @code{stringprep_check_version} would simply +pass on the call to @code{check_version}. + +There are two uses of the interface. The first is a way to provide +for applications to find out the version number of the library it +uses. The application may contain diagnostic code such as: + +@example + printf ("Stringprep version: header %s library %s", + STRINGPREP_VERSION, + stringprep_check_version (NULL)); +@end example + +Separating the library and header file version can be useful when +searching for version mismatch related problems. + +The second uses is as a rudimentary test of proper library version, by +making sure the application get a library version that is the same, or +newer, than the header file used when building the application. This +doesn't catch all problems, libraries may change backwards incompatibly +in later versions, but enable applications to require a certain +minimum version before it may proceed. + +Typical uses look like: + +@example + /* Check version of libgcrypt. */ + if (!gcry_check_version (GCRYPT_VERSION)) + die ("version mismatch\n"); +@end example + @node Invoking gnulib-tool @chapter Invoking gnulib-tool