Name

       App::Sqitch - Sensible database change management

Synopsis

         use App::Sqitch;
         exit App::Sqitch->go;

Description

       This module provides the implementation for sqitch. You probably want to read its
       documentation, or the tutorial. Unless you want to hack on Sqitch itself, or provide
       support for a new engine or command. In which case, you will find this API documentation
       useful.

Interface

   Class Methods
       "go"

         App::Sqitch->go;

       Called from "sqitch", this class method parses command-line options and arguments in
       @ARGV, parses the configuration file, constructs an App::Sqitch object, constructs a
       command object, and runs it.

   Constructor
       "new"

         my $sqitch = App::Sqitch->new(\%params);

       Constructs and returns a new Sqitch object. The supported parameters include:

       "options"
       "user_name"
       "user_email"
       "editor"
       "verbosity"

   Accessors
       "user_name"

       "user_email"

       "editor"

       "options"

         my $options = $sqitch->options;

       Returns a hashref of the core command-line options.

       "config"

         my $config = $sqitch->config;

       Returns the full configuration, combined from the project, user, and system configuration
       files.

       "verbosity"

   Instance Methods
       "run"

         $sqitch->run('echo', '-n', 'hello');

       Runs a system command and waits for it to finish. Throws an exception on error. Does not
       use the shell, so arguments must be passed as a list. Use "shell" to run a command and its
       arguments as a single string.

       "target"
           The name of the target, as passed.

       "uri"
           A database URI object, to be used to connect to the target database.

       "registry"
           The name of the Sqitch registry in the target database.

       If the $target argument looks like a database URI, it will simply returned in the hash
       reference. If the $target argument corresponds to a target configuration key, the target
       configuration will be returned, with the "uri" value a upgraded to a URI object. Otherwise
       returns "undef".

       "shell"

         $sqitch->shell('echo -n hello');

       Shells out a system command and waits for it to finish. Throws an exception on error.
       Always uses the shell, so a single string must be passed encapsulating the entire command
       and its arguments. Use "quote_shell" to assemble strings into a single shell command. Use
       "run" to execute a list without a shell.

       "quote_shell"

         my $cmd = $sqitch->quote_shell('echo', '-n', 'hello');

       Assemble a list into a single string quoted for execution by "shell". Useful for combining
       a specified command, such as "editor()", which might include the options in the string,
       for example:

         $sqitch->shell( $sqitch->editor, $sqitch->quote_shell($file) );

       "capture"

         my @files = $sqitch->capture(qw(ls -lah));

       Runs a system command and captures its output to "STDOUT". Returns the output lines in
       list context and the concatenation of the lines in scalar context.  Throws an exception on
       error.

       "probe"

         my $git_version = $sqitch->capture(qw(git --version));

       Like "capture", but returns just the "chomp"ed first line of output.

       "spool"

         $sqitch->spool($sql_file_handle, 'sqlite3', 'my.db');
         $sqitch->spool(\@file_handles, 'sqlite3', 'my.db');

       Like run, but spools the contents of one or ore file handle to the standard input the
       system command. Returns true on success and throws an exception on failure.

       "trace"

       "trace_literal"

         $sqitch->trace_literal('About to fuzzle the wuzzle.');
         $sqitch->trace('Done.');

       Send trace information to "STDOUT" if the verbosity level is 3 or higher.  Trace messages
       will have "trace: " prefixed to every line. If it's lower than 3, nothing will be output.
       "trace" appends a newline to the end of the message while "trace_literal" does not.

       "debug"

       "debug_literal"

         $sqitch->debug('Found snuggle in the crib.');
         $sqitch->debug_literal('ITYM "snuggie".');

       Send debug information to "STDOUT" if the verbosity level is 2 or higher.  Debug messages
       will have "debug: " prefixed to every line. If it's lower than 2, nothing will be output.
       "debug" appends a newline to the end of the message while "debug_literal" does not.

       "info"

       "info_literal"

         $sqitch->info('Nothing to deploy (up-to-date)');
         $sqitch->info_literal('Going to frobble the shiznet.');

       Send informational message to "STDOUT" if the verbosity level is 1 or higher, which, by
       default, it is. Should be used for normal messages the user would normally want to see. If
       verbosity is lower than 1, nothing will be output.  "info" appends a newline to the end of
       the message while "info_literal" does not.

       "comment"

       "comment_literal"

         $sqitch->comment('On database flipr_test');
         $sqitch->comment_literal('Uh-oh...');

       Send comments to "STDOUT" if the verbosity level is 1 or higher, which, by default, it is.
       Comments have "# " prefixed to every line. If verbosity is lower than 1, nothing will be
       output. "comment" appends a newline to the end of the message while "comment_literal" does
       not.

       "emit"

       "emit_literal"

         $sqitch->emit('core.editor=emacs');
         $sqitch->emit_literal('Getting ready...');

       Send a message to "STDOUT", without regard to the verbosity. Should be used only if the
       user explicitly asks for output, such as for "sqitch config --get core.editor". "emit"
       appends a newline to the end of the message while "emit_literal" does not.

       "vent"

       "vent_literal"

         $sqitch->vent('That was a misage.');
         $sqitch->vent_literal('This is going to be bad...');

       Send a message to "STDERR", without regard to the verbosity. Should be used only for error
       messages to be printed before exiting with an error, such as when reverting failed
       changes. "vent" appends a newline to the end of the message while "vent_literal" does not.

       "page"

       "page_literal"

         $sqitch->page('Search results:');
         $sqitch->page("Here we go\n");

       Like "emit()", but sends the output to a pager handle rather than "STDOUT".  Unless there
       is no TTY (such as when output is being piped elsewhere), in which case it is sent to
       "STDOUT". "page" appends a newline to the end of the message while "page_literal" does
       not. Meant to be used to send a lot of data to the user at once, such as when display the
       results of searching the event log:

         $iter = $engine->search_events;
         while ( my $change = $iter->() ) {
             $sqitch->page(join ' - ', @{ $change }{ qw(change_id event change) });
         }

       "warn"

       "warn_literal"

         $sqitch->warn('Could not find nerble; using nobble instead.');
         $sqitch->warn_literal("Cannot read file: $!\n");

       Send a warning messages to "STDERR". Warnings will have "warning: " prefixed to every
       line. Use if something unexpected happened but you can recover from it. "warn" appends a
       newline to the end of the message while "warn_literal" does not.

       "prompt"

         my $ans = $sqitch->('Why would you want to do this?', 'because');

       Prompts the user for input and returns that input. Pass in an optional default value for
       the user to accept or to be used if Sqitch is running unattended. An exception will be
       thrown if there is no prompt message or if Sqitch is unattended and there is no default
       value.

       "ask_yes_no"

         if ( $sqitch->ask_yes_no('Are you sure?', 1) ) { # do it! }

       Prompts the user with a "yes" or "no" question. Returns true if the user replies in the
       affirmative and false if the reply is in the negative. If the optional second argument is
       passed and true, the answer will default to the affirmative. If the second argument is
       passed but false, the answer will default to the negative. When a translation library is
       in use, the affirmative and negative replies from the user should be localized variants of
       "yes" and "no", and will be matched as such. If no translation library is in use, the
       answers will default to the English "yes" and "no".

       If the user inputs an invalid value three times, an exception will be thrown.  An
       exception will also be thrown if there is no message. As with "prompt()", an exception
       will be thrown if Sqitch is running unattended and there is no default.

       "ask_y_n"

       This method has been deprecated in favor of "ask_yes_no()" and will be removed in a future
       version of Sqitch.

   Constants
       "ISWIN"

         my $app = 'sqitch' . ( ISWIN ? '.bat' : '' );

       True when Sqitch is running on Windows, and false when it's not.

Author

       David E. Wheeler <david@justatheory.com>

License

       Copyright (c) 2012-2022 iovation Inc., David E. Wheeler

       Permission is hereby granted, free of charge, to any person obtaining a copy of this
       software and associated documentation files (the "Software"), to deal in the Software
       without restriction, including without limitation the rights to use, copy, modify, merge,
       publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
       to whom the Software is furnished to do so, subject to the following conditions:

       The above copyright notice and this permission notice shall be included in all copies or
       substantial portions of the Software.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
       INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
       PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
       FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
       OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
       DEALINGS IN THE SOFTWARE.