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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:43:11 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:43:11 +0000 |
commit | fc22b3d6507c6745911b9dfcc68f1e665ae13dbc (patch) | |
tree | ce1e3bce06471410239a6f41282e328770aa404a /upstream/archlinux/man3/NDBM_File.3perl | |
parent | Initial commit. (diff) | |
download | manpages-l10n-fc22b3d6507c6745911b9dfcc68f1e665ae13dbc.tar.xz manpages-l10n-fc22b3d6507c6745911b9dfcc68f1e665ae13dbc.zip |
Adding upstream version 4.22.0.upstream/4.22.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'upstream/archlinux/man3/NDBM_File.3perl')
-rw-r--r-- | upstream/archlinux/man3/NDBM_File.3perl | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/upstream/archlinux/man3/NDBM_File.3perl b/upstream/archlinux/man3/NDBM_File.3perl new file mode 100644 index 00000000..9408a783 --- /dev/null +++ b/upstream/archlinux/man3/NDBM_File.3perl @@ -0,0 +1,158 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. +.ie n \{\ +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds C` +. ds C' +'br\} +.\" +.\" Escape single quotes in literal strings from groff's Unicode transform. +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" +.\" If the F register is >0, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. +.\" +.\" Avoid warning from groff about undefined register 'F'. +.de IX +.. +.nr rF 0 +.if \n(.g .if rF .nr rF 1 +.if (\n(rF:(\n(.g==0)) \{\ +. if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. if !\nF==2 \{\ +. nr % 0 +. nr F 2 +. \} +. \} +.\} +.rr rF +.\" ======================================================================== +.\" +.IX Title "NDBM_File 3perl" +.TH NDBM_File 3perl 2024-02-11 "perl v5.38.2" "Perl Programmers Reference Guide" +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH NAME +NDBM_File \- Tied access to ndbm files +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 2 +\& use Fcntl; # For O_RDWR, O_CREAT, etc. +\& use NDBM_File; +\& +\& tie(%h, \*(AqNDBM_File\*(Aq, \*(Aqfilename\*(Aq, O_RDWR|O_CREAT, 0666) +\& or die "Couldn\*(Aqt tie NDBM file \*(Aqfilename\*(Aq: $!; aborting"; +\& +\& # Now read and change the hash +\& $h{newkey} = newvalue; +\& print $h{oldkey}; +\& ... +\& +\& untie %h; +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +\&\f(CW\*(C`NDBM_File\*(C'\fR establishes a connection between a Perl hash variable and +a file in NDBM_File format;. You can manipulate the data in the file +just as if it were in a Perl hash, but when your program exits, the +data will remain in the file, to be used the next time your program +runs. +.PP +Use \f(CW\*(C`NDBM_File\*(C'\fR with the Perl built-in \f(CW\*(C`tie\*(C'\fR function to establish +the connection between the variable and the file. The arguments to +\&\f(CW\*(C`tie\*(C'\fR should be: +.IP 1. 4 +The hash variable you want to tie. +.IP 2. 4 +The string \f(CW"NDBM_File"\fR. (Ths tells Perl to use the \f(CW\*(C`NDBM_File\*(C'\fR +package to perform the functions of the hash.) +.IP 3. 4 +The name of the file you want to tie to the hash. +.IP 4. 4 +Flags. Use one of: +.RS 4 +.ie n .IP """O_RDONLY""" 2 +.el .IP \f(CWO_RDONLY\fR 2 +.IX Item "O_RDONLY" +Read-only access to the data in the file. +.ie n .IP """O_WRONLY""" 2 +.el .IP \f(CWO_WRONLY\fR 2 +.IX Item "O_WRONLY" +Write-only access to the data in the file. +.ie n .IP """O_RDWR""" 2 +.el .IP \f(CWO_RDWR\fR 2 +.IX Item "O_RDWR" +Both read and write access. +.RE +.RS 4 +.Sp +If you want to create the file if it does not exist, add \f(CW\*(C`O_CREAT\*(C'\fR to +any of these, as in the example. If you omit \f(CW\*(C`O_CREAT\*(C'\fR and the file +does not already exist, the \f(CW\*(C`tie\*(C'\fR call will fail. +.RE +.IP 5. 4 +The default permissions to use if a new file is created. The actual +permissions will be modified by the user's umask, so you should +probably use 0666 here. (See "umask" in perlfunc.) +.SH DIAGNOSTICS +.IX Header "DIAGNOSTICS" +On failure, the \f(CW\*(C`tie\*(C'\fR call returns an undefined value and probably +sets \f(CW$!\fR to contain the reason the file could not be tied. +.ie n .SS """ndbm store returned \-1, errno 22, key ""..."" at ...""" +.el .SS "\f(CWndbm store returned \-1, errno 22, key ""..."" at ...\fP" +.IX Subsection "ndbm store returned -1, errno 22, key ""..."" at ..." +This warning is emitted when you try to store a key or a value that +is too long. It means that the change was not recorded in the +database. See BUGS AND WARNINGS below. +.SH "SECURITY AND PORTABILITY" +.IX Header "SECURITY AND PORTABILITY" +\&\fBDo not accept NDBM files from untrusted sources.\fR +.PP +On modern Linux systems these are typically GDBM files, which are not +portable across platforms. +.PP +The GDBM documentation doesn't imply that files from untrusted sources +can be safely used with \f(CW\*(C`libgdbm\*(C'\fR. +.PP +Systems that don't use GDBM compatibilty for ndbm support will be +using a platform specific library, possibly inherited from BSD +systems, where it may or may not be safe to use an untrusted file. +.PP +A maliciously crafted file might cause perl to crash or even expose a +security vulnerability. +.SH "BUGS AND WARNINGS" +.IX Header "BUGS AND WARNINGS" +There are a number of limits on the size of the data that you can +store in the NDBM file. The most important is that the length of a +key, plus the length of its associated value, may not exceed 1008 +bytes. +.PP +See "tie" in perlfunc, perldbmfilter, Fcntl |