Add log.add_log_file()

log.add_log_file(path) allows to pass a file path log messages will
be written into. Special characters (e.g. console color codes) will
be removed from the messages.

Signed-off-by: Jan Lindemann <jan@janware.com>

tools/python/jwutils/log.py

@@ -4,7 +4,7 @@ from __future__ import print_function
 
 from typing import List, Tuple, Optional, Any
 
-import sys, re, io, syslog, inspect
+import sys, re, io, syslog, inspect, unicodedata
 
 from os.path import basename
 from datetime import datetime
@@ -29,6 +29,9 @@ _special_chars = {
 
 _special_char_regex = re.compile("(%s)" % "|".join(map(re.escape, _special_chars.keys())))
 
+_all_control_chars   = ''.join(chr(c) for c in range(sys.maxunicode) if unicodedata.category(chr(c)) in {'Cc'})
+_clean_str_regex     = re.compile('(\033\[[0-9]*m|[%s])' % re.escape(_all_control_chars))
+
 EMERG                = int(syslog.LOG_EMERG)
 ALERT                = int(syslog.LOG_ALERT)
 CRIT                 = int(syslog.LOG_CRIT)
@@ -66,8 +69,10 @@ f_default            = [ f_position, f_stderr, f_prio, f_color ]
 
 _flags               = set(f_default)
 _log_prefix          = ''
+_clean_log_prefix    = ''
 _file_name_len       = 20
 _module_name_len     = 50
+_log_file_streams    = []
 
 _short_prio_str      = {
     EMERG            : '<Y>',
@@ -178,20 +183,25 @@ def slog(prio: int, *args, only_printable: bool=False, **kwargs) -> None: # expo
     if f_color in _flags:
         color_on, color_off = console_color_chars(prio)
 
-    msg += _log_prefix
+    margs = ''
-
     if len(args):
-        margs = ''
         for a in args:
             margs += ' ' + str(a)
         if only_printable:
             margs = _special_char_regex.sub(lambda mo: _special_chars[mo.string[mo.start():mo.end()]], margs)
             margs = re.sub('[\x01-\x1f]', '.', margs)
-        msg += color_on + margs + color_off
+
+    for file in _log_file_streams:
+        print(msg + _clean_log_prefix + margs, file=file)
+
+    msg += _log_prefix
 
     if not len(msg):
         return
 
+    if len(margs):
+        msg += color_on + margs + color_off
+
     files = []
     if 'capture' in kwargs:
         files.append(kwargs['capture'])
@@ -285,17 +295,21 @@ def set_flags(flags: str|None) -> str: # export
 
 def append_to_prefix(prefix: str) -> str: # export
     global _log_prefix
+    global _clean_log_prefix
     r = _log_prefix
     if prefix:
         _log_prefix += prefix
+        _clean_log_prefix = _clean_str_regex.sub('', _log_prefix)
     return r
 
 def remove_from_prefix(count) -> str: # export
     if isinstance(count, str):
         count = len(count)
     global _log_prefix
+    global _clean_log_prefix
     r = _log_prefix
     _log_prefix = _log_prefix[:-count]
+    _clean_log_prefix = _clean_str_regex.sub('', _log_prefix)
     return r
 
 def set_filename_length(l: int) -> int: # export
@@ -311,3 +325,8 @@ def set_module_name_length(l: int) -> int: # export
     if l:
         _module_name_len = l
     return r
+
+def add_log_file(path: str) -> None: # export
+    global _log_file_streams
+    fd = open(path, 'w', buffering=1)
+    _log_file_streams.append(fd)