embedding Python script in shell scripts

[Skaperen]

the "here-doc" approach is what i used. i never heard it called that (i called it "embedded input"). i never participated in a bash forum ... all they had at the time were mailing lists and i don't like mailing lists ... so that may explain never seeing that terminology. i am glad there is a forum around for Python. anyway, it worked just fine.

i had previously organized this (originally a "one off") script with a bunch of functions so i could keep lines relatively short (max 184, my text screen width) and separate pipelines. the functions had "awk" commands that were not working. i rewrote them 3 times and gave up and switched to Python. the first coding in Python worked. now i am thinking of reducin these 3 functions to just 1 to simplify the pipelines that call them.

in theory, i could have done it all in Python. but i already had a bash script to gather the data (a bunch of ssh and rsync calls) and at first i thought this would be a quickie mod. it wasn't.

as for which way to embed is best, i'd say just do the whole thing in Python. but in some cases, especially with pre-existing code, it can be better to make parts in another language. in the case of a part being in Python, it could be a separate Python script. but for many things, i like to keep things all in on file if it can remain readable. for Python in bash, i was hoping it would be simple enough to remain readable. i was certain it could be made to work. just how simple was my big question. fortunately the "here-doc" approach was quite simple.

#!/bin/bash
doit() {
    python3 /proc/self/fd/4 4<<EOF
print('this is python')
EOF
}

echo foo
doit
doit
echo bar
exit 0

i didn't need to use the -c option, which i thought would make things less readable.

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if a command line option like "+4" could be added to mean: read the code from the specified file descriptor, this would have been even simpler.