form_field - Linux
Overview
form_field manipulates form fields in multi-part forms. It can get/set specific fields and headers in a multi-part form, simplifying interaction with complex form data.
Syntax
form_field [-a] [-d] [-i FORMAT] [-o FORMAT] [-p PARAM] [-r PARAM] [-s SEPARATOR] [-t PARAM] FILE...
Options/Flags
- -a: (append) Append to existing forms.
- -d: (delete) Delete specified field(s).
- -i FORMAT: (in) Input format (defaults to "autodetect").
- -o FORMAT: (out) Output format (defaults to "autodetect").
- -p PARAM: (put) Set specified field(s) to value.
- -r PARAM: (replace) Replace specified header(s) with value.
- -s SEPARATOR: (separator) Header-value separator (defaults to "=").
- -t PARAM: (truncate) Truncate specified header(s).
Examples
Get field value
form_field -i multipart file.txt -p 'name=John'
Set field value
form_field -i multipart file.txt -a -p 'name=Jane'
Delete field
form_field -i multipart file.txt -d 'name=John'
Replace header
form_field -r 'Content-Type=multipart/form-data' file.txt
Common Issues
- Incorrect input format: Ensure the input file is a valid multi-part form.
- Duplicate field names: When appending to existing forms, field names must be unique.
- Empty output: Check that the output format is compatible with the desired output.
Integration
form_field can be combined with:
- curl: Interact with web forms interactively.
- wget: Download multi-part form responses.
- sed: Manipulate form data using text-based commands.