Arch::Backend - Arch backend feature specific functions

       Mikhael Goikhman (migo@homemail.com--Perl-GPL/arch-perl--devel).

       This  module  uses heuristics and does not (intend to) provide the perfect information. Requires constant
       updating.

       A set of helper functions suitable for GNU Arch related projects in Perl.

       Higher (object oriented) levels of Arch/Perl library make use of these helper functions to query certain
       aspects (like incompatible features) of the actual arch backend used.

       The following functions are available:

       arch_backend, arch_backend_name, arch_backend_version, is_tla, is_baz, has_archive_setup_cmd,
       has_file_diffs_cmd, has_register_archive_name_arg, has_tree_version_dir_opt, has_tree_id_cmd,
       has_set_tree_version_cmd, has_cache_feature, get_cache_config, has_commit_version_arg,
       has_commit_files_separator, has_revlib_patch_set_dir.

       arch_backend [exe]
           Return or set the arch backend executable, like "/opt/bin/tla" or "baz-1.3".

           By default, the arch backend executable is taken from environment variable $ARCH_BACKEND (or $TLA, or
           $BAZ). If no environment variable is set, then "tla" is used.

       arch_backend_name
           Return the brand name of the arch backend, "tla" or "baz".

       arch_backend_version
           Return the arch backend version, like "1.3.1".

       is_tla
           Return true if arch_backend_name is "tla".

       is_baz
           Return true if arch_backend_name is "baz".

       has_archive_setup_cmd
           Return true if the arch backend has "archive-setup" command. baz removed this command.

       has_file_diffs_cmd
           Return true if the arch backend has "file-diffs" command. It was renamed to "file-diff" in tla-1.3.

       has_register_archive_name_arg
           Return  true  if the arch backend's "register-archive" command supports two positional arguments, one
           of which is archive name. baz-1.3 removed such syntax;  the  previous  baz  versions  supported  this
           syntax, but it was useless, since the archive was accessed anyway.

       has_tree_version_dir_opt
           Return true if the arch backend's "tree-version" command supports "-d" options. This is true for baz.

       has_tree_id_cmd
           Return true if the arch backend has "tree-id" command.  This is true for baz.

       has_set_tree_version_cmd
           Return  true if the arch backend has "set-tree-version" command.  baz removed this command and merged
           it into "tree-version".

       has_cache_feature
           Return true if the arch backend supports Arch Cache feature.  This is true for baz.

       get_cache_config
           Return hash with the following keys: dir - directory of the local cache (or undef if not applicable).

       has_commit_version_arg
           Return true if the arch backend's "commit" command supports version argument.  baz-1.4  removed  this
           functionality.

       has_commit_files_separator
           Return  true if the arch backend's "commit" command requires "--" argument to separate files. baz-1.4
           removed this separator.

       has_revlib_patch_set_dir
           Return true if the arch backend's creates  ,,patch-set  subdirectory  in  revision  library.  baz-1.4
           removed this functionality.

       Arch::Backend - Arch backend feature specific functions

       For more information, see tla, baz, Arch.

perl v5.20.2                                       2005-10-23                                 Arch::Backend(3pm)

           use Arch::Backend qw(arch_backend is_baz has_file_diffs_cmd);

           my $exe = arch_backend();
           print "Not in tree, try '$exe init-tree'\n";

           my $version = Arch::Backend::arch_backend_version;
           print "Using baz $version as a backend\n" if is_baz();

           my $cmd = has_file_diffs_cmd()
               ? "file-diffs"
               : "file-diff";
           Arch::Util::run_tla($cmd, $filename);