feat(cli): add 'pwn errno --list' + perror-string lookup (#2657)

CHANGELOG.md

@@ -75,6 +75,7 @@ The table below shows which release corresponds to each branch, and what date th
 
 ## 5.0.0 (`dev`)
 
+- [#2727][2727] feat(cli): add 'pwn errno --list' + perror-string lookup
 - [#2677][2677] refactor: replace unsafe eval with safeeval.const in ROP cache loading
 - [#2675][2675] feat(term): add zellij support
 - [#2652][2652] Make setting the context.terminal to kitty more user friendly
@@ -187,6 +188,7 @@ The table below shows which release corresponds to each branch, and what date th
 [2720]: https://github.com/Gallopsled/pwntools/pull/2720
 [2702]: https://github.com/Gallopsled/pwntools/pull/2702
 [2722]: https://github.com/Gallopsled/pwntools/pull/2722
+[2727]: https://github.com/Gallopsled/pwntools/pull/2727
 
 ## 4.15.1
 

pwnlib/commandline/errno.py

@@ -11,37 +11,100 @@
 )
 
 parser.add_argument(
-    'error', help='Error message or value', type=str
+    'error', help='Error message or value (errno number, errno name, or perror string)',
+    nargs='?', type=str
 )
+parser.add_argument(
+    '-l', '--list', action='store_true',
+    help='List every known errno (number, name, perror string).'
+)
+parser.add_argument(
+    '-s', '--search', action='store_true',
+    help='Treat the argument as a perror substring and print every matching errno.'
+)
+
+
+def _iter_known_errnos():
+    """Yield ``(value, name, message)`` tuples for every errno code visible to
+    the standard library on this platform, sorted by numeric value.
+    """
+    for value, name in sorted(errno.errorcode.items()):
+        yield value, name, os.strerror(value)
+
+
+def _print_errno(value, name=None, message=None):
+    if name is None:
+        name = errno.errorcode.get(value, '')
+    if message is None:
+        message = os.strerror(value)
+    if name:
+        print('#define %s %d' % (name, value))
+    else:
+        print('#define <unknown> %d' % value)
+    print(message)
+
+
+def _search_errnos(needle):
+    """Return errnos whose ``strerror`` text contains ``needle`` (case-insensitive)."""
+    needle = needle.lower()
+    return [(v, n, m) for v, n, m in _iter_known_errnos() if needle in m.lower()]
+
 
 def main(args):
-  try:
-    value = int(args.error, 0)
+    if args.list:
+        for value, name, message in _iter_known_errnos():
+            print('%-3d %-10s %s' % (value, name, message))
+        return
+
+    if args.error is None:
+        parser.error('the following arguments are required: error (or pass --list)')
+
+    if args.search:
+        matches = _search_errnos(args.error)
+        if not matches:
+            print("No errno matched %r" % args.error)
+            return
+        for value, name, message in matches:
+            _print_errno(value, name, message)
+            print()
+        return
 
-    if value < 0:
-      value = -value
+    try:
+        value = int(args.error, 0)
 
-    if 0x100000000 - value < 0x200:
-      value = 0x100000000 - value
+        if value < 0:
+            value = -value
 
-    if value not in errno.errorcode:
-      print("No errno for %s" % value)
-      return
+        if 0x100000000 - value < 0x200:
+            value = 0x100000000 - value
 
-    name = errno.errorcode[value]
+        if value not in errno.errorcode:
+            print("No errno for %s" % value)
+            return
 
-  except ValueError:
-    name = args.error.upper()
+        name = errno.errorcode[value]
 
-    if not hasattr(errno, name):
-      print("No errno for %s" % name)
-      return
+    except ValueError:
+        candidate = args.error.upper()
 
-    value = getattr(errno, name)
+        if hasattr(errno, candidate):
+            name = candidate
+            value = getattr(errno, name)
+        else:
+            # Fall back to a substring search against perror messages so
+            # ``pwn errno 'Cannot allocate memory'`` resolves to ENOMEM.
+            matches = _search_errnos(args.error)
+            if not matches:
+                print("No errno for %s" % args.error)
+                return
+            for value, name, message in matches:
+                _print_errno(value, name, message)
+                if len(matches) > 1:
+                    print()
+            return
 
+    _print_errno(value, name)
 
-  print('#define', name, value)
-  print(os.strerror(value))
 
 if __name__ == '__main__':
     common.main(__file__, main)