#! /usr/bin/env python
# A rather specialized script to make sure that a symbolic link named
# RCS exists pointing to a real RCS directory in a parallel tree
# referenced as RCStree in an ancestor directory.
# (I use this because I like my RCS files to reside on a physically
# different machine).
import os
def main():
rcstree = 'RCStree'
rcs = 'RCS'
if os.path.islink(rcs):
print `rcs`, 'is a symlink to', `os.readlink(rcs)`
return
if os.path.isdir(rcs):
print `rcs`, 'is an ordinary directory'
return
if os.path.exists(rcs):
print `rcs`, 'is a file?!?!'
return
#
p = os.getcwd()
up = ''
down = ''
# Invariants:
# (1) join(p, down) is the current directory
# (2) up is the same directory as p
# Ergo:
# (3) join(up, down) is the current directory
#print 'p =', `p`
while not os.path.isdir(os.path.join(p, rcstree)):
head, tail = os.path.split(p)
#print 'head =', `head`, '; tail =', `tail`
if not tail:
print 'Sorry, no ancestor dir contains', `rcstree`
return
p = head
up = os.path.join(os.pardir, up)
down = os.path.join(tail, down)
#print 'p =', `p`, '; up =', `up`, '; down =', `down`
there = os.path.join(up, rcstree)
there = os.path.join(there, down)
there = os.path.join(there, rcs)
if os.path.isdir(there):
print `there`, 'already exists'
else:
print 'making', `there`
makedirs(there)
print 'making symlink', `rcs`, '->', `there`
os.symlink(there, rcs)
def makedirs(p):
if not os.path.isdir(p):
head, tail = os.path.split(p)
makedirs(head)
os.mkdir(p, 0777)
main()
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