.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42) .\" .\" 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 .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . 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 "IO::Capture::Stdout 3pm" .TH IO::Capture::Stdout 3pm "2022-10-13" "perl v5.34.0" "User Contributed Perl Documentation" .\" 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" IO::Capture::Stdout \- Capture any output sent to STDOUT .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 2 \& # Generic example (Just to give the overall view) \& use IO::Capture::Stdout; \& \& $capture = IO::Capture::Stdout\->new(); \& \& $capture\->start(); # STDOUT Output captured \& print STDOUT "Test Line One\en"; \& print STDOUT "Test Line Two\en"; \& print STDOUT "Test Line Three\en"; \& $capture\->stop(); # STDOUT output sent to wherever it was before \*(Aqstart\*(Aq \& \& # In \*(Aqscalar context\*(Aq returns next line \& $line = $capture\->read; \& print "$line"; # prints "Test Line One" \& \& $line = $capture\->read; \& print "$line"; # prints "Test Line Two" \& \& # move line pointer to line 1 \& $capture\->line_pointer(1); \& \& $line = $capture\->read; \& print "$line"; # prints "Test Line One" \& \& # Find out current line number \& $current_line_position = $capture\->line_pointer; \& \& # In \*(AqList Context\*(Aq return an array(list) \& @all_lines = $capture\->read; \& \& # More useful example 1 \- "Using in module tests" \& # Note: If you don\*(Aqt want to make users install \& # the IO::Capture module just for your tests, \& # you can just install in the t/lib directory \& # of your module and use the lib pragma in \& # your tests. \& \& use lib "t/lib"; \& use IO::Capture::Stdout; \& \& use Test::More; \& \& my $capture = IO::Capture::Stdout\->new; \& $capture\->start \& \& # execute with a bad parameter to make sure get \& # an error. \& \& ok( ! $test("Bad Parameter") ); \& \& $capture\->stop(); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" The module \f(CW\*(C`IO::Capture::Stdout\*(C'\fR, is derived from the abstract class \f(CW\*(C`IO::Capture\*(C'\fR. See IO::Capture. The purpose of the module (as the name suggests) is to capture any output sent to \f(CW\*(C`STDOUT\*(C'\fR. After the capture is stopped, the \s-1STDOUT\s0 filehandle will be reset to the previous location. E.g., If previously redirected to a file, when \&\f(CW\*(C`IO::Capture\->stop\*(C'\fR is called, output will start going into that file again. .PP Note: This module won't work with the perl function, \fBsystem()\fR, or any other operation involving a \fBfork()\fR. If you want to capture the output from a system command, it is faster to use \fBopen()\fR or back-ticks. .PP .Vb 1 \& my $output = \`/usr/sbin/ls \-l 2>&1\`; .Ve .SH "METHODS" .IX Header "METHODS" .SS "new" .IX Subsection "new" .IP "\(bu" 4 Creates a new capture object. .IP "\(bu" 4 An object can be reused as needed, so will only need to do one of these. .RS 4 .IP "\(bu" 4 Be aware, any data previously captured will be discarded if a new capture session is started. .RE .RS 4 .RE .SS "start" .IX Subsection "start" .IP "\(bu" 4 Start capturing data into the \f(CW\*(C`IO::Capture\*(C'\fR Object. .IP "\(bu" 4 Can \fBnot\fR be called on an object that is already capturing. .IP "\(bu" 4 Can \fBnot\fR be called while \s-1STDOUT\s0 tied to an object. .IP "\(bu" 4 \&\f(CW\*(C`undef\*(C'\fR will be returned on an error. .SS "stop" .IX Subsection "stop" .IP "\(bu" 4 Stop capturing data and point \s-1STDOUT\s0 back to it's previous output location I.e., untie \s-1STDOUT\s0 .SS "read" .IX Subsection "read" .IP "\(bu" 4 In \fIScalar Context\fR .RS 4 .IP "\(bu" 4 Lines are read from the buffer at the position of the \f(CW\*(C`line_pointer\*(C'\fR, and the pointer is incremented by one. .Sp .Vb 1 \& $next_line = $capture\->read; .Ve .RE .RS 4 .RE .IP "\(bu" 4 In \fIList Context\fR .RS 4 .IP "\(bu" 4 The array is returned. The \f(CW\*(C`line_pointer\*(C'\fR is not affected. .Sp .Vb 1 \& @buffer = $capture\->read; .Ve .RE .RS 4 .RE .IP "\(bu" 4 Data lines are returned exactly as they were captured. You may want to use \f(CW\*(C`chomp\*(C'\fR on them if you don't want the end of line character(s) .Sp .Vb 4 \& while (my $line = $capture\->read) { \& chomp $line; \& $cat_line = join \*(Aq\*(Aq, $cat_line, $line; \& } .Ve .SS "line_pointer" .IX Subsection "line_pointer" .IP "\(bu" 4 Reads or sets the \f(CW\*(C`line_pointer\*(C'\fR. .Sp .Vb 2 \& my $current_line = $capture\->line_pointer; \& $capture\->line_pointer(1); .Ve .SH "SUB-CLASSING" .IX Header "SUB-CLASSING" .SS "Adding Features" .IX Subsection "Adding Features" If you would like to sub-class this module to add a feature (method) or two, here is a couple of easy steps. Also see IO::Capture::Overview. .IP "1." 4 Give your package a name .Sp .Vb 1 \& package MyPackage; .Ve .IP "2." 4 Use this \f(CW\*(C`IO::Capture::Stdout\*(C'\fR as your base class like this: .Sp .Vb 1 \& package MyPackage; \& \& use base qw/IO::Capture::Stdout/; .Ve .IP "3." 4 Add your new method like this .Sp .Vb 1 \& package MyPackage; \& \& use base qw/IO::Capture::Stdout/; \& \& sub grep { \& my $self = shift; \& \& for $line ( \& } .Ve .SH "See Also" .IX Header "See Also" IO::Capture::Overview .PP IO::Capture .PP IO::Capture::Stderr .SH "AUTHORS" .IX Header "AUTHORS" Mark Reynolds reynolds@sgi.com .PP Jon Morgan jmorgan@sgi.com .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright (c) 2003, Mark Reynolds. All Rights Reserved. This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.