[pp:exec] support more replacement fields for '--exec' (#4633)

- {_directory}
- {_filename}
- {_path} (alias for {})

docs/options.md

@@ -121,11 +121,13 @@
     --write-tags                Write image tags to separate text files
     --mtime-from-date           Set file modification times according to 'date'
                                 metadata
-    --exec CMD                  Execute CMD for each downloaded file. Example:
-                                --exec "convert {} {}.png && rm {}"
+    --exec CMD                  Execute CMD for each downloaded file. Supported
+                                replacement fields are {} or {_path},
+                                {_directory}, {_filename}. Example: --exec
+                                "convert {} {}.png && rm {}"
     --exec-after CMD            Execute CMD after all files were downloaded
-                                successfully. Example: --exec-after "cd {} &&
-                                convert * ../doc.pdf"
+                                successfully. Example: --exec-after "cd
+                                {_directory} && convert * ../doc.pdf"
     -P, --postprocessor NAME    Activate the specified post processor
     -O, --postprocessor-option OPT
                                 Additional '<key>=<value>' post processor

gallery_dl/option.py

@@ -510,6 +510,8 @@ def build_parser():
         dest="postprocessors", metavar="CMD",
         action=AppendCommandAction, const={"name": "exec"},
         help=("Execute CMD for each downloaded file. "
+              "Supported replacement fields are "
+              "{} or {_path}, {_directory}, {_filename}. "
               "Example: --exec \"convert {} {}.png && rm {}\""),
     )
     postprocessor.add_argument(
@@ -518,7 +520,8 @@ def build_parser():
         action=AppendCommandAction, const={
             "name": "exec", "event": "finalize"},
         help=("Execute CMD after all files were downloaded successfully. "
-              "Example: --exec-after \"cd {} && convert * ../doc.pdf\""),
+              "Example: --exec-after \"cd {_directory} "
+              "&& convert * ../doc.pdf\""),
     )
     postprocessor.add_argument(
         "-P", "--postprocessor",

gallery_dl/postprocessor/exec.py

@@ -12,6 +12,7 @@ from .common import PostProcessor
 from .. import util, formatter
 import subprocess
 import os
+import re
 
 
 if util.WINDOWS:
@@ -32,6 +33,7 @@ class ExecPP(PostProcessor):
         args = options["command"]
         if isinstance(args, str):
             self.args = args
+            self._sub = re.compile(r"\{(_directory|_filename|_path|)\}").sub
             execute = self.exec_string
         else:
             self.args = [formatter.parse(arg) for arg in args]
@@ -69,11 +71,8 @@ class ExecPP(PostProcessor):
         if archive and archive.check(pathfmt.kwdict):
             return
 
-        if pathfmt.realpath:
-            args = self.args.replace("{}", quote(pathfmt.realpath))
-        else:
-            args = self.args.replace("{}", quote(pathfmt.realdirectory))
-
+        self.pathfmt = pathfmt
+        args = self._sub(self._replace, self.args)
         self._exec(args, True)
 
         if archive:
@@ -90,5 +89,13 @@ class ExecPP(PostProcessor):
         self.log.debug("Running '%s'", args)
         subprocess.Popen(args, shell=shell)
 
+    def _replace(self, match):
+        name = match.group(1)
+        if name == "_directory":
+            return quote(self.pathfmt.realdirectory)
+        if name == "_filename":
+            return quote(self.pathfmt.filename)
+        return quote(self.pathfmt.realpath)
+
 
 __postprocessor__ = ExecPP

test/test_postprocessor.py

@@ -168,7 +168,7 @@ class ExecTest(BasePostprocessorTest):
 
     def test_command_string(self):
         self._create({
-            "command": "echo {} && rm {};",
+            "command": "echo {} {_path} {_directory} {_filename} && rm {};",
         })
 
         with patch("subprocess.Popen") as p:
@@ -178,7 +178,11 @@ class ExecTest(BasePostprocessorTest):
             self._trigger(("after",))
 
         p.assert_called_once_with(
-            "echo {0} && rm {0};".format(self.pathfmt.realpath), shell=True)
+            "echo {0} {0} {1} {2} && rm {0};".format(
+                self.pathfmt.realpath,
+                self.pathfmt.realdirectory,
+                self.pathfmt.filename),
+            shell=True)
         i.wait.assert_called_once_with()
 
     def test_command_list(self):