David Boyce

# NAME

ClearCase::Argv - ClearCase-specific subclass of Argv

# SYNOPSIS

    # OO interface
use ClearCase::Argv;
ClearCase::Argv->dbglevel(1);
# Note how the command, flags, and arguments are separated ...
my $describe = ClearCase::Argv->new('desc', [qw(-fmt %c)], "."); # Run the basic "ct describe" command.$describe->system;
# Run it with with stderr turned off.
$describe->stderr(0)->system; # Run it without the flags.$describe->system('-');
# Run it through a pipe.
$describe->pipecb(sub { print shift; return 1; });$describe->pipe;
# Create label type XX iff it doesn't exist
ClearCase::Argv->new(qw(mklbtype -nc XX))
if ClearCase::Argv->new(qw(lstype lbtype:XX))->stderr(0)->qx;
# Create a multitool ipc session in autochomp mode
ctsystem('mklbtype', ['-global'], 'FOO') && exit $? >> 8; my @vobs = ctqx({autochomp=>1}, 'lsvob -s'); ctpipe('lsview', ['-l'], sub { print "GOT: " . shift() . "\n"; 1 }); These interfaces may also be imported via the :functional tag:  use ClearCase::Argv ':functional'; # CAREFUL PROGRAMMERS WANTED If you're the kind of programmer who tends to execute whole strings such as system("cleartool pwv -s") reflexively or who uses backquotes in a void context, this module won't help you much because it can't easily support those styles. These are deprecated techniques regardless of whether you use ClearCase::Argv and you should strive to overcome them. # STICKINESS A subtlety: when an execution attribute is set in a void context, it's "sticky", meaning that it's set until explicitly reset. But in a non-void context the new value is temporary or "non-sticky"; it's pushed on a stack and popped off after being read once. This applies to both class and instance uses. It's done this way to allow the following locutions:  ClearCase::Argv->stdout(0); # turn off stdout for all objects$obj1->stdout(0);           # turn off stdout for this object, forever
$obj2->stdout(0)->system; # suppress stdout, this time only This allows you to set up an object with various sticky attributes and keep it around, executing it at will and overriding other attrs temporarily. In the example below, note that another way of setting sticky attrs is illustrated:  my$obj = ClearCase::Argv->new({autofail=>1, autochomp=>1});
my $view =$obj->argv('pwv -s')->qx;
my $exists =$obj->argv('lstype', 'brtype:FOO')->autofail(0)->qx;

Here we keep an object with attrs 'autochomp' and 'autofail' (autofail means to exit on any failure) around and use it to exec whichever commands we want. While checking to see if a type exists, we suppress autofail temporarily. On the next use the object will have both attributes again.

# BUGS

I suspect there are still some special quoting situations unaccounted for in the quote method. This will need to be refined over time. Bug reports or patches gratefully accepted.

Commands using a format option defining a multi-line output fail in many cases in fork mode, because of the underlying Argv module.

ClearCase::Argv will use IPC::ChildSafe if it finds it, which may introduce differences of behavior with the newer code to replace it. It should probably just drop it, unless explicitly driven to use it.

Autochomp should be equivalent in all modes on all platforms, which is hard to test (ipc w/wo IPC::ChildSafe, ctcmd, on Unix and Windows, with system and qx...). The autochomp setting should not affect system() in ipc mode!? Hopefully it doesn't anymore. Problem: change not satisfactorily tested on Windows yet (where the output prior to the last change seemed ok...)

Argv uses the first-found of three different modules for cloning, and Marc Girod suspects that only the first one (Clone, in recent versions) performs correctly with GLOB objects... work-around in place.

The use of 'cleartool -status' was restored, because of the failure to handle interactive comments without it. The ClearCase bug, with setview exiting the interactive session to the shell (Found from 2002.05.00 to 7.0.1 and resulting in a hang under the ipc mode) is worked around by starting a new coprocess in the new view.

Cygwin support on Windows.

The 'exit' cleartool command is dangerous in ipc mode: it will stop the coprocess unconditionally, without Argv updating its ipc status, and the ipccount. This will affect any other users of the same coprocess. Another symptom of the problem is a 'broken pipe' error. Argv writes to the coprocess, but obviously fails to read anything coming back.

Some multiline commands work in the fork mode, but not in the ipc one.

E.g. $ct->des(['-fmt', "%[owner]p\n"], 'vob:.')->system This example is easily rewritten to work in both modes as either: $ct->des(['-fmt', '%[owner]p\n'], 'vob:.')->system
\$ct->des([qw(-fmt %[owner]p\n)], 'vob:.')->system

# PORTABILITY

ClearCase::Argv should work on all supported ClearCase platforms and versions. It's currently maintained on Solaris 9 and Windows XP with CC 7.0 using Perl5.8.x. Viability on other platforms and/or earlier versions is untestable by me.

Marc Girod's testing environment: Solaris 10 (sparc and i386), GNU/Linux 2.6, and Windows Vista, without IPC::ChildSafe, with Clone. Perl 5.8.8, 5.10, 5.14, 5.16. Tatiana Shpichko's testing environment: RedHat Linux 4, with and without CtCmd, and Windows XP without CtCmd.

# FILES

This is a subclass of Argv and thus requires Argv to be installed. ClearCase::CtCmd is required for ctcmd mode in Unix. In Windows, Win32-Process-Info or Win32::ToolHelp is required for pipe support.