New & keybinding to run an external application with cell value as ar…

…gv[1]

CHANGELOG.md

@@ -5,6 +5,10 @@
 - New keybinding in a row-list buffer: `U` will unmark all marked rows (deselects them for
   deletion).
 
+- New keybinding in a row-list buffer: `&` will run an application asynchronously with the current
+  cell value as first commandline argument. This complements the existing `!` keybinding which runs
+  a Unix-like filter shell command with the current cell value as input.
+
 - Fixes to the interaction between marking rows for deletion and refetching/redrawing the row-list
   table. A refetch will now unmark all rows, because data in PostgreSQL may have changed since rows
   were marked for deletion leading to inconsistent line numbers.

doc/src/row-list.md

@@ -22,6 +22,7 @@ The following keys are bound when the point is located in the row-list table:
 | <kbd>RET</kbd>                  | Edit the value at point in the minibuffer, or jump to foreign table.                 |
 | <kbd>w</kbd>                    | Edit the value at point in a widget-based buffer.                                    |
 | <kbd>!</kbd>                    | Run a shell command on the value at point, replacing the output if prefix argument.  |
+| <kbd>&</kbd>                    | Run a program asynchronously with the value at point as first arugment.              |
 | <kbd>Alt</kbd>-<kbd>u</kbd>     | Upcase the content of the current cell and update PostgreSQL.                        |
 | <kbd>Alt</kbd>-<kbd>l</kbd>     | Downcase the content of the current cell and update PostgreSQL.                      |
 | <kbd>Alt</kbd>-<kbd>c</kbd>     | Capitalize the content of the current cell and update PostgreSQL.                    |
@@ -56,6 +57,41 @@ The following keys are bound when the point is located in the row-list table:
 
 
 
+## Run a shell command or an external application on cell value
+
+There are two methods for running an external (non-Emacs) command on the current cell value:
+
+- Run a Unix filter shell command with the cell value as input: press <kbd>!</kbd>. This is works
+  similarly to the standard Emacs `shell-command` command, which is bound to
+  <kbd>M</kbd>-<kbd>!</kbd>. If called with a prefix argument, it will update the database value to
+  the result of the shell command.
+
+- Run a program asynchronously with the cell value as its first commandline argument: press
+  <kbd>&amp;</kbd>. This works similarly to the standard Emacs `async-shell-command`, which is bound
+  to <kbd>M</kbd>-<kbd>&amp;</kbd>.
+
+For example, to count the number of characters in the current cell, type
+
+    ! wc -c
+
+To downcase the value of a text cell (and modify the value in the database) use
+
+    C-u ! tr '[:upper:]' '[:lower]'
+
+To reverse the order of the characters in the cell (and modify the value in
+the database), use
+
+    C-u ! rev
+
+On a Microsoft Windows machine, you may need to install the [MSYS2](https://www.msys2.org/)
+commandline tools for these examples to work.
+
+If the current cell contains a file name, you can launch your system’s default application for that
+filename extension by typing <kbd>&amp;</kbd> then entering `xdg-open` (or `open` on a MacOS
+machine).
+
+
+
 ## Follow foreign key references
 
 A column that references data in a foreign table (`FOREIGN KEY`) will be shown in blue. If you type

pgmacs.el

@@ -598,9 +598,11 @@ PRIMARY-KEYS."
 (defvar pgmacs--shell-command-history nil)
 
 (defun pgmacs--shell-command-on-value (current-row primary-keys)
-  "Run a shell command with the current cell value as input.
-Normally display output in the echo area. If called with a prefix argument,
-place the current cell value with the output.
+  "Run a Unix filter shell command with the current cell value as input.
+
+When called without a prefix argument, output is diplayed in the echo area.
+When called with a prefix argument, replace the current cell value with the output
+(updating the database).
 
 For example, to count the number of characters in the current cell,
 
@@ -637,6 +639,26 @@ Works on the CURRENT-ROW and on a table with PRIMARY-KEYS."
       ;; displayed pgmacstbl.
       (pgmacs--setf-cell current-row primary-keys get-value))))
 
+(defvar pgmacs--async-command-history nil)
+
+(defun pgmacs--async-command-on-value (&rest _ignore)
+  "Run a command asynchronously with the current cell value as first argument.
+The command should be the name of a program, which will be searched for in
+`exec-path' (it is run via `start-process', without a shell). Command output will
+be displayed in a buffer called *PGmacs async command*.
+
+For example, if the cell contains a filename, you can open the filename in the
+default application on your system by entering `xdg-open' (or `open' on a MacOS
+machine).
+
+Works on the CURRENT-ROW and on a table with PRIMARY-KEYS."
+  (pgmacs-funcall-cell
+   (lambda (cell-value)
+     (let* ((prompt "Async command: ")
+            (cmd (read-string prompt nil 'pgmacs--async-command-history))
+            (buf (get-buffer-create "*PGmacs async command*")))
+       (start-process "PGmacs-async-command" buf cmd cell-value)))))
+
 (defun pgmacs--downcase-value (current-row primary-keys)
   "Downcase the value in the cell at point and update PostgreSQL.
 Operates on the CURRENT-ROW and on a table with PRIMARY-KEYS."
@@ -1469,9 +1491,7 @@ Table names are schema-qualified if the schema is non-default."
       (when (y-or-n-p (format "Really run SQL '%s'?" sql))
         (let ((res (pg-exec pgmacs--con sql)))
           (pgmacs--notify "%s" (pg-result res :status))))))
-  (pgmacs--display-table pgmacs--table)
-  (pgmacs--update-row-markings))
-
+  (pgmacs--display-table pgmacs--table))
 
 (defun pgmacs--display-procedures (&rest _ignore)
   "Open a buffer displaying the FUNCTIONs and PROCEDURES defined in this database."
@@ -1592,7 +1612,8 @@ Table names are schema-qualified if the schema is non-default."
       (shw "U" "Unmark all rows (deselect all for deletion)")
       (shw "x" "Delete marked rows")
       (shw "R" "Rename the current column")
-      (shw "!" "Run a shell command on the value of the current cell")
+      (shw "!" "Run a filter-like shell command with current cell value as input")
+      (shw "&" "Run a program with the value of current cell as first argument")
       (shw "M-u" "Upcase the value of the current cell")
       (shw "M-l" "Downcase the value of the current cell")
       (shw "M-c" "Capitalize the value of the current cell")
@@ -1880,6 +1901,7 @@ The CENTER-ON and WHERE-FILTER arguments are mutually exclusive."
                        :actions `("RET" (lambda (row) (pgmacs--table-list-dwim row ',primary-keys))
                                   "w" (lambda (row) (pgmacs--edit-value-widget row ',primary-keys))
                                   "!" (lambda (row) (pgmacs--shell-command-on-value row ',primary-keys))
+                                  "&" pgmacs--async-command-on-value
                                   "M-u" (lambda (row) (pgmacs--upcase-value row ',primary-keys))
                                   "M-l" (lambda (row) (pgmacs--downcase-value row ',primary-keys))
                                   "M-c" (lambda (row) (pgmacs--capitalize-value row ',primary-keys))