sage_select

#!/usr/bin/env python3

# The purpose of this script is to detect all installed sage versions and
# offer to symlink to a selected version in the project (i.e. ~/bin/sage -> ...)

import os, sys
if len(sys.argv) == 1:
    print("%s <version>"%sys.argv[0])
    versions = []
    # Searching the entire PATH is slightly slower than just searching one or
    # two paths, but this is OK, since it's relatively rarely used.
    for path in os.environ['PATH'].split(':'):
        if os.path.exists(path):
            versions = versions + [x.split('-')[-1] for x in os.listdir(path) if x.startswith('sage-')]
    versions = list(sorted(set(versions)))
    print("Available versions: %s"%(', '.join(versions)))
    sys.exit(1)

VERSION=sys.argv[1]
target = "sage-%s"%VERSION
for path in os.environ['PATH'].split(':'):
    if os.path.exists(path):
        for x in os.listdir(path):
            if x == target:
                cmd = "cd && mkdir -p ~/bin/ && cd ~/bin/ && rm -f sage && ln -sf %s/%s sage"%(path, target)
                print(cmd)
                os.system(cmd)
                print("Making default sage %s by creating ~/bin/sage symbolic link:"%target)
                print("You should probably restart your project (in 'Settings' -> 'Project Control').")
                sys.exit(0)

print("%s does not exist in your PATH"%target)
sys.exit(1)