save roundup-admin history between sessions.

Also load ~/.roundup_admin_rlrc (rlrc readline run commands) file to
set history-size persistently, allow user to use vi mode etc.

Author: rouilj

CHANGES.txt

@@ -124,6 +124,9 @@ Features:
   dump_dbm_sessions_db.py, contributors.py (John Rouillard)
 - roundup/msgfile.py can now be called as 'python msgfmt.py de.po de.mo'
   to compile a translation file if msgfmt is missing. (John Rouillard)
+- save roundup-admin history between sessions. Load
+  ~/.roundup_admin_rlrc file to set history-size persistently. Add
+  pragma history_length to override for a session. (John Rouillard)
 
 
 2023-07-13 2.3.0

doc/admin_guide.txt

@@ -1407,6 +1407,33 @@ and feed it to roundup-admin on standard input. E.G.
 
 .. index:: ! roundup-admin; usage in scripts
 
+Using Interactively
+-------------------
+
+You can edit the command line using left/right arrow keys to move the
+cursor. Using the up/down arrow keys moves among commands. It will
+save your commands between roundup-admin sessions. This is supported
+on Unix/Linux and Mac's. On windows you should install the pyreadline3
+package (see `installation documentation`_).
+
+Using the ``history_length`` pragma you can set the saved history size
+for just one session.
+
+You can add initialization commands to ``~/.roundup_admin_rlrc``. It
+will be loaded when roundup-admin starts. This is the mechanism to
+persistently set the number of history commands, change editing modes
+(Vi vs. Emacs). Note that redefining the history file will not work.
+
+If you are using GNU readline, ``set history-size 10``. If your
+installation uses libedit (macs), it should be possible to
+persistently set the history size using ``history size
+10``. Pyreadline3 can set history length using
+``history_length(10)``. See the older documentation for example syntax:
+https://pythonhosted.org/pyreadline/usage.html.persistently.
+
+History is saved to the file ``.roundup_admin_history`` in your home
+directory (for windows usually ``\Users\<username>``.
+
 Using with the shell
 --------------------
 

roundup/admin.py

@@ -114,6 +114,7 @@ def __init__(self):
             'display_header': False,
             'display_protected': False,
             'indexer_backend': "as set in config.ini",
+            'history_length': -1,
             '_reopen_tracker': False,
             'savepoint_limit': self._default_savepoint_setting,
             'show_retired': "no",
@@ -2087,9 +2088,30 @@ def interactive(self):
         """
         print(_('Roundup %s ready for input.\nType "help" for help.')
                 % roundup_version)
+
+        initfile = os.path.join(os.path.expanduser("~"),
+                                ".roundup_admin_rlrc")
+        histfile = os.path.join(os.path.expanduser("~"),
+                                ".roundup_admin_history")
+
         try:
             import readline  # noqa: F401
+            readline.read_init_file(initfile)
+            try:
+                readline.read_history_file(histfile)
+            except FileNotFoundError:
+                # no history file yet
+                pass
+
+            # Default history length is unlimited.
+            # Set persistently in readline init file
+            # Pragma history_length allows setting on a per
+            #   invocation basis at startup
+            if self.settings['history_length'] != -1:
+                readline.set_history_length(
+                    self.settings['history_length'])
         except ImportError:
+            readline = None
             print(_('Note: command history and editing not available'))
 
         while 1:
@@ -2112,6 +2134,10 @@ def interactive(self):
             commit = self.my_input(_('There are unsaved changes. Commit them (y/N)? '))
             if commit and commit[0].lower() == 'y':
                 self.db.commit()
+
+        # looks like histfile is saved with mode 600
+        if readline:
+            readline.write_history_file(histfile)
         return 0
 
     def main(self):  # noqa: PLR0912, PLR0911

share/man/man1/roundup-admin.1

@@ -291,6 +291,30 @@ merged/updated config file is written to \fI<filename>\fP.
 Commands may be abbreviated as long as the abbreviation
 matches only one command, e.g. l == li == lis == list.
 
+.SH READLINE SUPPORT
+
+You can edit the command line and interact with history in
+roundup-admin's interactive mode. On Linux like systems, GNU Readline
+is required. On Mac's libedit can be used as well. On Windows
+pyreadline3 is required. See:
+https://docs.python.org/3/library/readline.html for details on
+readline.
+
+Roundup-admin will save the history between roundup-admin
+sessions. The commands are saved to the \fB.roundup_admin_history\fP
+file in the user's home directory.  You can set the pragma
+\fBhistory_length\fP on the roundup-admin command line to change the
+amount of available and stored history for the session.
+
+If you are using GNU readline, you can persistently change the history
+size by adding: \fBset history-size 100\fP to the init file
+\fB.roundup_admin_rlrc\fP located in the user's home directory.
+
+Mac users using libedit should be able to persistently save history
+and set the history size by adding \fBhistory size 100\fP.
+
+Users of pyreadline3 can use: \fBhistory_length(100)\fP.
+
 .SH SECURITY NOTES
 
 The \fB-u user\fP setting does not currently operate like a