Files
OCRmyPDF/ocrmypdf/exec/__init__.py
2018-02-24 12:38:58 -08:00

49 lines
1.4 KiB
Python

# © 2016 James R. Barlow: github.com/jbarlow83
"""Wrappers to manage subprocess calls"""
import os
import re
import sys
from subprocess import run, STDOUT, PIPE, CalledProcessError
from ..exceptions import MissingDependencyError
def get_program(name):
"Check environment variables for overrides to this program"
envvar = 'OCRMYPDF_' + name.upper()
return os.environ.get(envvar, name)
def get_version(program, *,
version_arg='--version', regex=r'(\d+(\.\d+)*)'):
"Get the version of the specified program, "
args_prog = [
get_program(program),
version_arg
]
try:
proc = run(
args_prog, close_fds=True, universal_newlines=True,
stdout=PIPE, stderr=STDOUT, check=True)
output = proc.stdout
except CalledProcessError as e:
if get_program(program) == program:
raise MissingDependencyError(
"Could not find program '{}' on the PATH".format(
program)) from e
else:
raise MissingDependencyError(
"Could not find program '{}'".format(
get_program(program))) from e
try:
version = re.match(regex, output.strip()).group(1)
except AttributeError as e:
raise MissingDependencyError(
("The program '{}' did not report its version. "
"Message was:\n{}").format(program, output)
)
return version