Passing arguments to a embedded python script in bash

Question

I'm having difficulties passing arguments to a embedded bash script.

 #!/bin/bash/
 function my_function() {
 MYPARSER="$1" python - <<END
 <<Some Python Code>>

 class MyParser(OptionParser):
 def format_epilog(self, formatter):
    return self.epilog

 parser=MyParser(version=VER, usage=USAGE, epilog=DESC)

 parser.add_option("-s", "--Startdir", dest="StartDir", 
               metavar="StartDir"
             )
 parser.add_option("-r", "--report", dest="ReportDir", 
               metavar="ReportDir"
             )
<<More Python Code>>

 END
 }

 foo="-s /mnt/folder -r /storagefolder/"
 my_function "$foo"

I've read Steve's Blog: Embedding python in bash scripts which helped but I'm still unable to pass the argument. I've tried both parser and myparser as environmental variables.

Is it as simple as defining $2 and passing them individually?

Thanks

@CharlesDuffy - I am working with a completed python script (a co-workers) but because of portability need to embed into a bash script I wrote. The python script requires me to declare -s and -r to run. I had thought (perhaps wrongly) that when I called the my_function with the variable it would pass it as "python script -s /mnt/folder -r /storagefolder". — ImNotLeet
– ImNotLeet, Commented Jun 25, 2015 at 21:34
Now, as a separate issue, don't ever pass store an argument list in a scalar string variable (which you're doing here). Argument lists belong in arrays, and yes, bash supports them. — Charles Duffy
– Charles Duffy, Commented Jun 25, 2015 at 21:36
As an aside -- using the function keyword in bash is bad form: It's incompatible with POSIX sh, but -- unlike most of bash's incompatibilities -- gives you absolutely no improvement in expressiveness or functionality over the POSIX-standard syntax. Just use myfunc() {, not function myfunc() {. — Charles Duffy
– Charles Duffy, Commented Jun 25, 2015 at 21:40

Charles Duffy · Accepted Answer · 2015-06-25 21:33:33Z

4

You're overcomplicating this rather a lot. Why mess with a parser where

value="hello" python -c 'import os; print os.environ["value"]'

Or, for a longer script:

value="hello" python <<'EOF'
import os
print os.environ["value"]
EOF

If you need to set sys.argv for compatibility with existing code:

python - first second <<<'import sys; print sys.argv'

Thus:

args=( -s /mnt/folder -r /storagefolder/ )
python - "${args[@]}" <<'EOF'
import sys
print sys.argv # this is what an OptionParser will be looking at by default.
EOF

answered Jun 25, 2015 at 21:33

Charles Duffy

299k43 gold badges441 silver badges496 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

David Maddox Over a year ago

How would you pass multiple values?

Charles Duffy Over a year ago

The same way you pass a single value. a=b c=d python ... puts both a and c in os.environ. And the args example already passes multiple values.

Collectives™ on Stack Overflow

Passing arguments to a embedded python script in bash

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related