stgit/pager.py

   1 import os
   2 import shutil
   3 import subprocess
   4 import sys
   5
   6 from stgit.out import out
   7
   8
   9 def pager(msg):
  10     pager = _choose_pager()
  11     if not sys.stdin.isatty() or not sys.stdout.isatty() or not pager:
  12         return out.stdout_bytes(msg)
  13     else:
  14         return _run_pager(pager, msg)
  15
  16
  17 def _run_pager(pager, msg):
  18     proc = subprocess.Popen(pager, shell=True, stdin=subprocess.PIPE)
  19     try:
  20         proc.stdin.write(msg)
  21     except (KeyboardInterrupt, OSError):
  22         pass
  23     finally:
  24         proc.stdin.close()
  25     while True:
  26         try:
  27             proc.wait()
  28             break
  29         except KeyboardInterrupt:
  30             pass
  31
  32
  33 def _choose_pager():
  34     for k in ['GIT_PAGER', 'PAGER', 'MANPAGER']:
  35         pager = os.environ.get(k)
  36         if pager:
  37             return pager
  38     for pager in ['less', 'more']:
  39         if shutil.which(pager):
  40             return pager
  41     return None