second commit

env/lib/python3.11/site-packages/shellingham/posix/__init__.py

@@ -0,0 +1,112 @@
+import os
+import re
+
+from .._core import SHELL_NAMES, ShellDetectionFailure
+from . import proc, ps
+
+# Based on QEMU docs: https://www.qemu.org/docs/master/user/main.html
+QEMU_BIN_REGEX = re.compile(
+    r"""qemu-
+        (alpha
+        |armeb
+        |arm
+        |m68k
+        |cris
+        |i386
+        |x86_64
+        |microblaze
+        |mips
+        |mipsel
+        |mips64
+        |mips64el
+        |mipsn32
+        |mipsn32el
+        |nios2
+        |ppc64
+        |ppc
+        |sh4eb
+        |sh4
+        |sparc
+        |sparc32plus
+        |sparc64
+    )""",
+    re.VERBOSE,
+)
+
+
+def _iter_process_parents(pid, max_depth=10):
+    """Select a way to obtain process information from the system.
+
+    * `/proc` is used if supported.
+    * The system `ps` utility is used as a fallback option.
+    """
+    for impl in (proc, ps):
+        try:
+            iterator = impl.iter_process_parents(pid, max_depth)
+        except EnvironmentError:
+            continue
+        return iterator
+    raise ShellDetectionFailure("compatible proc fs or ps utility is required")
+
+
+def _get_login_shell(proc_cmd):
+    """Form shell information from SHELL environ if possible."""
+    login_shell = os.environ.get("SHELL", "")
+    if login_shell:
+        proc_cmd = login_shell
+    else:
+        proc_cmd = proc_cmd[1:]
+    return (os.path.basename(proc_cmd).lower(), proc_cmd)
+
+
+_INTERPRETER_SHELL_NAMES = [
+    (re.compile(r"^python(\d+(\.\d+)?)?$"), {"xonsh"}),
+]
+
+
+def _get_interpreter_shell(proc_name, proc_args):
+    """Get shell invoked via an interpreter.
+
+    Some shells are implemented on, and invoked with an interpreter, e.g. xonsh
+    is commonly executed with an executable Python script. This detects what
+    script the interpreter is actually running, and check whether that looks
+    like a shell.
+
+    See sarugaku/shellingham#26 for rational.
+    """
+    for pattern, shell_names in _INTERPRETER_SHELL_NAMES:
+        if not pattern.match(proc_name):
+            continue
+        for arg in proc_args:
+            name = os.path.basename(arg).lower()
+            if os.path.isfile(arg) and name in shell_names:
+                return (name, arg)
+    return None
+
+
+def _get_shell(cmd, *args):
+    if cmd.startswith("-"):  # Login shell! Let's use this.
+        return _get_login_shell(cmd)
+    name = os.path.basename(cmd).lower()
+    if name == "rosetta" or QEMU_BIN_REGEX.fullmatch(name):
+        # If the current process is Rosetta or QEMU, this likely is a
+        # containerized process. Parse out the actual command instead.
+        cmd = args[0]
+        args = args[1:]
+        name = os.path.basename(cmd).lower()
+    if name in SHELL_NAMES:  # Command looks like a shell.
+        return (name, cmd)
+    shell = _get_interpreter_shell(name, args)
+    if shell:
+        return shell
+    return None
+
+
+def get_shell(pid=None, max_depth=10):
+    """Get the shell that the supplied pid or os.getpid() is running in."""
+    pid = str(pid or os.getpid())
+    for proc_args, _, _ in _iter_process_parents(pid, max_depth):
+        shell = _get_shell(*proc_args)
+        if shell:
+            return shell
+    return None