apenwarr-redo/docs/cookbook/container/default.sha256.do

#!/usr/bin/env python
"""Calculate the sha256 digest of a given file."""
import hashlib, os, subprocess, sys

subprocess.check_call([
    'redo-ifchange',
    sys.argv[2],
], close_fds=False)

h = hashlib.sha256()
f = open(sys.argv[2])
while 1:
    b = f.read(65536)
    if not b: break
    h.update(b)
open(sys.argv[3], 'w').write(h.hexdigest() + '\n')
cookbook/container: example of building+running docker containers. This got... long... and complicated. But I think it's a really good demonstration of getting redo to do complicated things elegantly. At least, I hope it is. 2019-01-02 23:46:01 -05:00			`#!/usr/bin/env python`
			`"""Calculate the sha256 digest of a given file."""`
			`import hashlib, os, subprocess, sys`

			`subprocess.check_call([`
			`'redo-ifchange',`
			`sys.argv[2],`
cookbook/container/default.sha256.do: use explicit close_fds=False. Some people have /usr/bin/python as a link to python3. The script is designed to work in either python2 or python3, but python3's subprocess model defaults to close_fds=True, which closes the jobserver fds and causes an error. Explicitly force close_fds=False to get identical behaviour on python2 and python3. Reported-by: Tharre <tharre3@gmail.com> 2019-05-15 15:17:29 -07:00			`], close_fds=False)`
cookbook/container: example of building+running docker containers. This got... long... and complicated. But I think it's a really good demonstration of getting redo to do complicated things elegantly. At least, I hope it is. 2019-01-02 23:46:01 -05:00
			`h = hashlib.sha256()`
			`f = open(sys.argv[2])`
			`while 1:`
			`b = f.read(65536)`
			`if not b: break`
			`h.update(b)`
			`open(sys.argv[3], 'w').write(h.hexdigest() + '\n')`