'\" t.TH zlibc.conf 5 27jun99 ZLIBC'\" t.de TQ.br.ns.TP \\$1...tr \(is'.tr \(if`.tr \(pd".ds St Zlibc.oh '\\*(St''%'.eh '%''\\*(St'.PP.SH Namezlibc.conf - zlibc's configuration file.SH WarningThis manpage has been automatically generated from zlibc's texinfodocumentation.  However, this process is only approximative, and someitems, such as crossreferences, footnotes and indices are lost in thistranslation process.  Indeed, this items have no appropriaterepresentation in the manpage format.  Thus I strongly advise you to usethe original texinfo doc..TP* \ \ To generate a printable copy from the texinfo doc, run the followingcommands: .nf.ft 3.in +0.3i    ./configure; make dvi; dvips zlibc.dvi.fi.in -0.3i.ft R.lp \&\fR.TP* \ \ To generate a html copy,  run: .nf.ft 3.in +0.3i    ./configure; make html.fi.in -0.3i.ft R.lp \&\fRA premade html can be found at:\&\fR\&\f(CW\(ifhttp://www.tux.org/pub/knaff/zlibc/zlibc.html\(is\fR.TP* \ \ To generate an info copy (browsable using emacs' info mode), run: .nf.ft 3.in +0.3i    ./configure; make info.fi.in -0.3i.ft R.lp \&\fR.PPThe texinfo doc looks most pretty when printed or as html.  Indeed, inthe info version certain examples are difficult to read due to thequoting conventions used in info..SH Description.PPTo get its configuration, zlibc first looks into the file described bythe environment variable \fR\&\f(CWLD_ZLIB_CONFFILE\fR (if any), then in\&\fR\&\f(CW\(if~/.zlibrc\(is\fR and finally in \fR\&\f(CW\(if/usr/local/etc/zlibc.conf\(is\fR(\fR\&\f(CW\(if/etc/zlibc.conf\(is\fR on Linux \fR\fR\fR).  If the desired information is found in neither ofthese files, the compiled-in defaults are used.  It is possible tosupply only part of the needed information in the configurationfiles. In that case, the missing information is retrieved from thecompiled-in defaults. This allows you to have really small runtimeconfiguration files, which only list the differences between the desiredconfiguration and the compiled-in configuration..PPIf an error occurs while parsing one of the configuration files, theoffending file is skipped, and the search continues with the nextfile. However, no error message is printed unless the environmentalvariable \fR\&\f(CWLD_ZLIB_VERBOSE\fR is turned on (i.e. set to \fR\&\f(CW1\fR orto \fR\&\f(CWon\fR )..PPIf two files contain contradictory information, the information in thefile which is scanned first is retained (usually \fR\&\f(CW\(if~/.zlibrc\(is\fR). Ifany flags have been set or unset using environmental variables, thesesettings override the flags specified in the configuration files..PPThe configuration files are read by each process. For each process, theyare read at most once, at the time when zlibc is first used (attempt toaccess a compressed file). Afterwards they are cached in the process'svirtual memory.  Thus, changing zlibc configuration files doesn'tgenerally have any effect on already running processes..PP.SH Overall\ structure.iX "c commands section".iX "c class section".iX "c Parsing order of configuration files.".PPThe zlibrc files consist of two sections: A \fIcommands\fR section(\(ifCommands line flags\(is) and a \fIclass definition\fR section(\(ifClass section\(is)..PPThe commands section describes how zlibc should behave depending onthe executable that it was called from.  Several commands are groupedtogether into \fIcommand classe\fR..PPThe class definition section describes how zlibc should behave dependingon the class of the command and the datafile opened..PPThe configuration file may contain comments in both sections: a commentstarts with a hash (\fR\&\f(CW#\fR) and stops at the end of the line..PPDashes (\fR\&\f(CW-\fR) and underbars (\fR\&\f(CW_\fR) may be used indifferently inall keywords..PP.SH Commands\ section.PP.SS General\ syntax\ of\ the\ commands\ section.iX "c commands section".PPThe format for a line in the "commands" section is as follows:.PP.(l I\&\fR\&\f(CWcommands "\fR\fIcmd1\fR\fR\&\f(CW"\fR [ \&... \fR\&\f(CW"\fR\fIcmdn\fR\fR\&\f(CW"\fR ] \fR\&\f(CWuse\fR \fIflags\fR \fR\&\f(CW"\fR\fIclass\fR\fR\&\f(CW"\fR\&\&.)l .PPIn this line, the \fIcmd1\fR \&... \fIcmdn\fR are the basenames of theprograms (commands) for which this line should apply.  The basename isthe name without the path, i.e. \fR\&\f(CWls\fR instead of\&\fR\&\f(CW/usr/bin/ls\fR. The command names should be enclosed in quotes.  Youmay also use the keyword \fR\&\f(CWdefault\fR (without quotes) to match allcommands..PPThe \fIflags\fR describe those aspects of zlibc's behaviour that areindependant from the datafile which is being accessed. These flags comein pairs.  The flags need not to be listed on a single \fR\&\f(CWcommands\fRline, they may occur in several places, even in several differentconfiguration files (for instance one in \fR\&\f(CW/etc/zlibc.conf\fR andanother one in \fR\&\f(CW~/.zlibrc\fR..PPIf two contradictory flags are found in the configuration files, the onewhich is seen first is taken..PPIf on the other hand a certain flag is not found at all in theconfiguration files, the compiled-in default for this flag is used. Thisis usually the second flag of each pair, described below(see section  Commands line flags)..PPThese flags can all be overridden by environmental variables.  When thecorresponding environmental variable is set to \fR\&\f(CW1\fR or to \fR\&\f(CWon\fR,the first flag is used, when it is set to \fR\&\f(CW0\fR or to \fR\&\f(CWoff\fR.  Ifthe environmental variables is set to neither of these 4 values, it isignored)..PPThe \fIclass\fR names the commands class that these commands belong to.If, for a given command, two \fR\&\f(CWcommands\fR lines give differentclasses, the one which is seen first is taken. No union of classes ismade, the classes are always treated as a whole. Thus, if you want tomake a change to a command class, you need to describe it in itsentirety..PPThe following example says that the \fR\&\f(CWtar\fR, \fR\&\f(CWcpio\fR, \fR\&\f(CWpax\fR,\&\fR\&\f(CWcp\fR and \fR\&\f(CWmv\fR show compressed files in a directory listing(\fR\&\f(CWreaddir_compr\fR flag), and are of class \fR\&\f(CWgeneric_safe\fR. .nf.ft 3.in +0.3icommands "tar" "cpio" "pax" "cp" "mv" use readdir_compr "generic_safe".fi.in -0.3i.ft R.lp \&\fR.PPThe class \fR\&\f(CWgeneric_safe\fR would then need to be described further inthe class section..PP.SS Available\ commands\ line\ flags.iX "v disable".iX "v enable".iX "v readdir_compr".iX "v readdir_uncompr".iX "v verbose".iX "v silent".PP.iX "c disabling zlibc (conf. file)".iX "c showing compressed files on a directory listing (conf. file)".iX "c debugging zlibc".PPThis section describes the flags which can be used on a \fR\&\f(CWcommands\fRline. All these flags come in pairs..PPThe table below describes each of these pairs.  The first word in theheader of each item is the non-default flag, the second word is thedefault flag, and the third word is the environmental variable by whichyou can override the settings from the configuration files. If thisenvironmental variable is turned on (set to 1), the non-default (first)flag is taken, if it is turned off (set to 0), the default (second) flagis taken..TP\&\fR\&\f(CWdisable\ /\ enable\ /\ LD_ZLIB_DISAB\fR\ The \fR\&\f(CWdisable\fR flag disables zlibc for the programs on this commandsline.  This is useful for compression and uncompression utilities.Without this flag, \fR\&\f(CWgunzip\fR would not work anymore, because itwould think that the uncompressed file exists already, and it wouldrefuse to overwrite this file..TP\&\fR\&\f(CWdisable_child\ /\ enable_child\ /\ LD_ZLIB_DISAB_CHILD\fR\ The \fR\&\f(CWdisable_child\fR flag disables zlibc for the programs started byprograms on this commands line. This is implemented by removeing alloccurrences of \fR\&\f(CWuncompress.o\fR from the LD_PRELOAD environmentvariable. This function is useful for programs such as xemacs, in orderto make sure that all launched subprograms return results consistentwith emacs itself (directory listings, etc).TP\&\fR\&\f(CWreaddir_compr\ /\ readdir_uncompr\ /\ LD_ZLIB_READDIR\fR\ The readdir function shows the uncompressed files (i.e. with theirtrailing \fR\&\f(CW.gz\fR extension) when the \fR\&\f(CWreaddir_compr\fR flag isset, and the compressed files otherwise..TP\&\fR\&\f(CWverbose\ /\ silent\ /\ LD_ZLIB_VERBOSE\fR\ When \fR\&\f(CWverbose\fR is set, zlibc prints informational messages..TP\&\fR\&\f(CWunlink\ /\ no_unlink\ /\ LD_ZLIB_UNLINK\fR\ If the \fR\&\f(CWunlink\fR flag is set, and if the user program tries tounlink a virtual (uncompressed) file, the package translates this callinto unlinking the real file. If the \fR\&\f(CWno_unlink\fR flag is set,requests to unlink virtual (uncompressed) files are silently ignored..PP.SH Class\ section.PPA command class definition describes thoseaspects of zlibc's behavior that depend on the name of the datafilewhich is being accessed. Command classes are identified by a name whichis matched against the \fIclass\fR parameter from the commands.  Theclass name should be enclosed between quotes both in the commands lineand in the class definition..PPThe class section contains descriptions of different command classes(i.e descriptions how datafiles should be uncompressed). Each classdefinition begins with a line of the following format:.PP.(l I\&\fR\&\f(CWclass "\fR\fIid\fR\fR\&\f(CW"\fR.)l .PPThe class \fIid\fR is the same string as the one used in the commandsline. The remaining lines of a class definition are as follows:.(l I[ [ \fIcriterion\fR ] [ \fR\&\f(CW"\fR\fIname\fR\fR\&\f(CW"\fR ]] \fImode\fR.)l .PPThe following example shows the definition of the class used for X-servers..PP .nf.ft 3.in +0.3i# X uses tmp files in its own directories.class "X"subdir "/usr/X11R6" usetmpfilesubdir "/usr/X386" usetmpfilesubdir "/usr/lib/X11" usetmpfileshowpipe.fi.in -0.3i.ft R.lp \&\fR.PPThis says that all compressed files who are in a subdirectory below\&\fR\&\f(CW\(if/usr/X11R6\(is\fR, \fR\&\f(CW\(if/usr/X386\(is\fR or \fR\&\f(CW\(if/usr/lib/X11\(is\fR aredecompressed using temporary files (\fR\&\f(CWusetmpfile\fR), and that filesfrom other directories are decompressed using pipes (\fR\&\f(CWshowpipe\fR).PPThe following examples illustrates a command class, named \fR\&\f(CWnopipe\fR,which always uses temporary files for decompression.(l I# generic class which uses temp files for all files.class "nopipe"usetmpfile.)l .PP.SS File\ selection\ Criteria.iX "c directory (selection criterion)".iX "c filename (selection criterion)".iX "c extension (selection criterion)".iX "c suffix (selection criterion)".iX "c basename (selection criterion)".iX "c doublespaced DOS filesystem".PPThe \fIcriterion \fR describes what parts of the filename should match:.TP\&\fR\&\f(CWfilename\fR\ The entire filename of the target data file must match\&\fIname\fR..TP\&\fR\&\f(CWbasename\fR\ The basename (filename without directory) of the target data file mustmatch \fIname\fR..TP\&\fR\&\f(CWdirectory\fR\ The data file must live in the directory \fIname\fR.  If the userprogram opens the file with an absolute pathname, that filename is usedas is.  If on the other hand the user program uses a relative pathname,zlibc uses the most direct path to the file (i.e. without symlinks)..TP\&\fR\&\f(CWsubdirectory\fR\ The data file must live in the directory \fIname\fR or in one of itssubdirectories. If the user program opens the file with an absolutepathname, that filename is used as is.  If on the other hand the userprogram uses a relative pathname, zlibc uses the most direct path to thefile (i.e. without symlinks)..TP\&\fR\&\f(CWsuffix\fR\ The data file's name must end in \fIname\fR.  This is useful forselecting files according to their extension..TP\&\fR\&\f(CWfilesystem\fR\ The data file must live on the same filesystem as \fIname\fR. Thiscriterion can for example be used for example to disable zlibc on adoublespaced filesystem (where zlibc would be redundant), or to switchoff uncompressed size reporting on an \fR\&\f(CWftpfs\fR filesystems\&\fR\fR..TP\&\fR\&\f(CWdefault\fR\ All data files match. All class definitions must have a default line,and this default line must be the last line of the definition. Thedefault criterion needs no 'name' parameter..TP\&\fR\&\f(CWall\fR\ All data files match. Unlike \fR\&\f(CWdefault\fR, this line needs not to bethe last line of the class definitions. Thus it is possible to specifyseveral \fR\&\f(CWall\fR lines for different aspects of \fR\&\f(CWzlibc\fRbehaviour..PPThe lines of each class definition are scanned in sequence, and, foreach aspect, the first matching line isadopted.  The class may be defined in another initialisation file, ifthis file is scanned later. The \fIcriterion\fR parameter may be omittedif it can be deduced from the \fIname\fR. In that case, the followingheuristics are used:.TP* \ \ \&\fIName\fRs beginning with a dot are considered as \fR\&\f(CWsuffix\fR..TP* \ \ \&\fIName\fRs beginning with a slash, but not ending with a slash areconsidered as \fIfilename\fR..TP* \ \ \&\fIName\fRs beginning and ending with a slash are considered as\&\fR\&\f(CWsubdirectory\fR..TP* \ \ A missing \fIname\fR is considered as \fR\&\f(CWdefault\fR..TP* \ \ All the other \fIname\fRs are considered as \fR\&\f(CWbasename\fR..PP\&\fR\fI\fI\fI.PP\&\fI.IP.IP.IP\&\fI\fI\fI\fI.IP\&\fI\fI\fI\fI.PP\&\fI.IP\&\fI.IP\&\fI.IP\&\fI.IP.PP\&\fI.PP\&\fI\fI\fI.IP\&\fI.IP\&\fI.IP.PP\&\fI.IP\&\fI.IP\&\fI.IP.PP\&\fI\fI\fI.PP\&\fI\fI\fI\fI.PP\&\fI\fI\fI.IP.PP