I am trying to create a bash script which passes its own argument onto a python script. I want it to work like this.
If I run it as this:
script.sh latest
Then within the bash script it runs a python script with the "latest" argument like this:
python script.py latest
Likewise if the bash script is run with the argument 123 then the python script as such:
python script.py 123
Can anyone help me understand how to accomplish this please?
In this case the trick is to pass however many arguments you have, including the case where there are none, and to preserve any grouping that existed on the original command line.
So, you want these three cases to work:
script.sh # no args
script.sh how now # some number
script.sh "how now" "brown cow" # args that need to stay quoted
There isn't really a natural way to do this because the shell is a macro language, so they've added some magic syntax that will just DTRT.
#!/bin/sh
python script.py "$@"
In the pythonscript script.py use getopt.getopt(args, options[, long_options]) to get the arguments.
Example:
import getopt, sys
def main():
try:
opts, args = getopt.getopt(sys.argv[1:], "ho:v", ["help", "output="])
except getopt.GetoptError as err:
# print help information and exit:
print str(err) # will print something like "option -a not recognized"
usage()
sys.exit(2)
output = None
verbose = False
for o, a in opts:
if o == "-v":
verbose = True
elif o in ("-h", "--help"):
usage()
sys.exit()
elif o in ("-o", "--output"):
output = a
else:
assert False, "unhandled option"
# ...
if __name__ == "__main__":
main()
A very goo buit-in parser is argparse. Yo can use it as follows:
import argparse
parser = argparse.ArgumentParser(description='Process some integers.')
parser.add_argument('integers', metavar='N', type=int, nargs='+',
help='an integer for the accumulator')
parser.add_argument('--sum', dest='accumulate', action='store_const',
const=sum, default=max,
help='sum the integers (default: find the max)')
args = parser.parse_args()
print(args.accumulate(args.integers))
In bash, arguments passed to the script are accessed with the $# notation (# being a number. Using $# exactly like that should give you the number of args passed). So if you wanted to pass arguments:
Calling the script:
`#script.sh argument`
Within the script:
python script.py "$1"
"$1" to preserve whitespace