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udippel
Asked: 2024-08-18 03:26:07 +0800 CST

How can I modify a variable / argument passed to a script online/inline

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I'm looking for passing a variable to script (I know how to do that), that will be echoed by the script in order to slightly modify that variable.

$ [scriptname] foo bar

where [scriptname] is the name of the program, and foo and bar the two arguments passed. [Edited for clarification, after comment:] The resulting file should be named foo_bar1, but with the option for the user to make minor modifications to this file name that one can't know beforehand. Therefore it could look like

$ [scriptname] foo bar
The output file name will be foo_bar1

And here I wished I could interactively use, like backslash, remove the 1 and replace it by underscore (_) and 2: The output file name will therefore be foo_bar_2 And this would subsequently be a known or new variable in the script, so that the results of this script can be written into an output file called foo_bar_2.
Reason for my question is, that the file names are not just 3 chars, but rather long, and contain specific data. So the user ought not (try to) re-type dozens of characters; often the output file name will be the one as proposed. The user will see it, most often just 'Enter'. Though also have the chance to add own, minor, modifications. [I hope this explains somewhat better what I need.?]

Is this possible? If yes, I'd gladly learn how to do that. And it isn't necessarily only the last number (I'd know how to remove/isolate it). But at times, I ought to be able to also call the output foofoo_bar_2.

scripts

1 Answers

  1. Best Answer

    Based on my understanding of what you are trying to do, I have written a bash script. It takes two arguments. The script will exit if exactly two arguments are not provided. If the script finds two arguments it will combine them with an _ in between and a 1 as the suffix to form a "filename". Then the script will present this "filename" to the user and the user will have an opportunity to edit it as they please.

    The script:

    Create a file called altname with the following contents:

    #!/bin/bash
# Purpose: This script takes two arguments and creates a filename with it.
#      Then it presents the user with the filename and an oppotunity to alter it.

# Check for two arguments
if [ $# -ne 2 ]; then
  echo 1>&2 "Usage: $0 arg1 arg2"
  exit 3
fi

# Create the proposed filename by adding "_" and "1"
filename="$1"_"$2"1

# Ask the user for approval or change
echo "This is the proposed filename."
read -e -i "$filename" -p "Hit Enter to accept or change:" filename
echo "the final filename is: $filename"

    Save the file. Open a terminal and run the script with the command:

    ./altname foo bar

This is the proposed filename.
Hit Enter to accept or change:foo_bar1

    You should see a prompt like above. Use the arrow keys, delete, backspace, etc. to alter the name and hit Enter. The script will then display the final filename.

    Hope this helps

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