Merge remote-tracking branch 'origin/fix_bad_file_descriptor' into fix_bad_file_descriptor

.pre-commit-config.yaml

@@ -8,7 +8,7 @@ default_language_version:
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: 'v0.5.5'
+    rev: 'v0.5.6'
     hooks:
       - id: ruff
         args: [., --fix, --exit-non-zero-on-fix]
@@ -18,7 +18,7 @@ repos:
         pass_filenames: false
 
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: 'v1.11.0'  # Use the sha / tag you want to point at
+    rev: 'v1.11.1'  # Use the sha / tag you want to point at
     hooks:
       - id: mypy
         pass_filenames: false

docs/bash_to_xsh.rst

@@ -1,11 +1,7 @@
 Bash to Xonsh Translation Guide
 ================================
-As you have probably figured out by now, xonsh is not ``sh``-lang compliant.
-If your muscles have memorized all of the Bash prestidigitations, this page
-will help you put a finger on how to do the equivalent task in xonsh.
-
-For shell scripts, the recommended file extension is ``xsh``, and shebang
-line is ``#!/usr/bin/env xonsh``.
+Xonsh relies primarily on the Python syntax and is not a suitable replacement for `sh` and is thus considered a non-POSIX shell.
+This page provides xonsh equivalents for common patterns in Bash.
 
 .. list-table::
     :widths: 30 30 40
@@ -14,6 +10,16 @@ line is ``#!/usr/bin/env xonsh``.
     * - Bash
       - Xonsh
       - Notes
+    * - No special object for represent session.
+      - ``__xonsh__``
+      - The ``__xonsh__`` object has all about current xonsh session e.g. ``__xonsh__.env``.
+        You can set ``X = __xonsh__`` to have a shortcut for ``X.env`` and similar.
+    * - ``script.sh``
+      - ``script.xsh``
+      - The recommended file extension is ``.xsh``.
+    * - ``#!/bin/bash``
+      - ``#!/usr/bin/env xonsh``
+      - Use ``xonsh`` in the shebang.
     * - ``echo --arg="val"``
 
         ``echo {}``
@@ -33,7 +39,8 @@ line is ``#!/usr/bin/env xonsh``.
         characters, words or brackets.
     * - ``IFS``
       - ``$XONSH_SUBPROC_OUTPUT_FORMAT``
-      - Changing the output representation and splitting.
+      - Changing the output representation and splitting. Also take a look into ``DecoratorAlias``
+        to have an ability to return object e.g. ``j = $(@json echo '{}')``.
     * - ``$NAME`` or ``${NAME}``
       - ``$NAME``
       - Look up an environment variable by name.
@@ -59,7 +66,7 @@ line is ``#!/usr/bin/env xonsh``.
     * - ``ENV1=VAL1 command``
       - ``$ENV1=VAL1 command``
 
-        or ``with ${...}.swap(ENV1=VAL1): command``
+        or ``with __xonsh__.env.swap(ENV1=VAL1): command``
       - Set temporary environment variable(s) and execute the command.
         Use the second notation with an indented block to execute many commands in the same context.
     * - ``alias ll='ls -la'``
@@ -135,7 +142,7 @@ line is ``#!/usr/bin/env xonsh``.
       - Xonsh publishes a handful of containers, primarily targeting CI and automation use cases.
         All of them are published on `Docker Hub <https://hub.docker.com/u/xonsh>`_.
     * - ``exit 1``
-      - ``exit(1)``
+      - ``exit 1`` or ``exit(1)``
       - Exiting from the current script.
 
 To understand how xonsh executes the subprocess commands try

news/fix_safe_readlines.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* Fixed exception "object has no attribute readlines" in case of redirect callable alias output.
+
+**Security:**
+
+* <news item>

xonsh/procs/pipelines.py

@@ -62,6 +62,8 @@ def SIGNAL_MESSAGES():
 
 def safe_readlines(handle, hint=-1):
     """Attempts to read lines without throwing an error."""
+    if handle is None:
+        return []
     try:
         lines = handle.readlines(hint)
     except OSError:
@@ -276,7 +278,7 @@ class CommandPipeline:
                     lines = b.splitlines(keepends=True)
                     yield from lines
                     self.end(tee_output=False)
-                elif self.captured == "stdout":
+                elif self.captured == "stdout" and stdout is not None:
                     b = stdout.read()
                     s = self._decode_uninew(b, universal_newlines=True)
                     self.lines = s.splitlines(keepends=True)