run_command.py revision a34e754dfd715b6f6338a2a4586da47e8fb3580c
import os
import sys
import tempfile
"""
run_command.py
Module for running SVG-generating commands in Inkscape extensions
Copyright (C) 2008 Stephen Silver
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
"""
# Run a command that generates an SVG file from an input file.
# On success, outputs the contents of the SVG file to stdout, and exits
# with a return code of 0.
# On failure, outputs an error message to stderr, and exits with a return
# code of 1.
def run(command_format, prog_name):
svgfile = tempfile.mktemp(".svg")
command = command_format % svgfile
msg = None
# In order to get a return code from the process, we use subprocess.Popen
# if it's available (Python 2.4 onwards) and otherwise use popen2.Popen3
# (Unix only). As the Inkscape package for Windows includes Python 2.5,
# this should cover all supported platforms.
try:
try:
from subprocess import Popen, PIPE
p = Popen(command, shell=True, stdout=PIPE, stderr=PIPE)
rc = p.wait()
out = p.stdout.read()
err = p.stderr.read()
except ImportError:
try:
from popen2 import Popen3
p = Popen3(command, True)
p.wait()
rc = p.poll()
out = p.fromchild.read()
err = p.childerr.read()
except ImportError:
# shouldn't happen...
msg = "Neither subprocess.Popen nor popen2.Popen3 is available"
if rc and msg is None:
msg = "%s failed:\n%s\n%s\n" % (prog_name, out, err)
except Exception, inst:
msg = "Error attempting to run %s: %s" % (prog_name, str(inst))
# If successful, copy the SVG file to stdout.
if msg is None:
if os.name == 'nt': # make stdout work in binary on Windows
import msvcrt
msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
try:
f = open(svgfile, "rb")
data = f.read()
sys.stdout.write(data)
f.close()
except IOError, inst:
msg = "Error reading temporary SVG file: %s" % str(inst)
# Clean up.
try:
os.remove(svgfile)
except Exception:
pass
# Ouput error message (if any) and exit.
if msg is not None:
sys.stderr.write(msg + "\n")
sys.exit(1)
else:
sys.exit(0)
# vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99