field_opts_on - Linux

Overview

field_opts_on is a versatile command-line tool for extracting specific fields from a given input text. It is commonly used to parse delimited data, such as CSV or TSV files, and select only the relevant columns or fields.

Syntax

field_opts_on [options] 'input string' [field1, field2, ...]

Options/Flags

  • -d, --delimiter: Specify the field delimiter. Default is "," (comma).
  • -s, --skip: Skip specified number of fields from the beginning. Default is 0.
  • -l, --limit: Limit output to the specified number of fields. Default is unlimited.
  • -f, --fields: Specify the fields to extract as a comma-separated list.
  • -n, --newlines: Enable new lines in output. Default is off.
  • -q, --quiet: Suppress error messages.
  • -h, --help: Display help message.

Examples

Extract specific columns from a CSV file:

field_opts_on -d "," -f name,age data.csv

Skip the first two fields and extract the third field:

field_opts_on -s 2 -l 1 data.csv

Extract the first and last fields with new lines:

field_opts_on -f 1,last -n data.csv

Common Issues

  • If the input string contains the delimiter character, enclose it in quotes.
  • Ensure the field numbers specified in -f correspond to the actual field positions in the input string.
  • Check the input text encoding if special characters are not parsed correctly.

Integration

Combine with other commands:

  • Use | to pipe the output of field_opts_on to other commands for further processing: 
    field_opts_on -f name data.csv | sort

Extract fields from a script:

#!/bin/sh
input="John Doe,30"
fields=$(field_opts_on -f name,age "$input")
echo "Name: $fields"

Related Commands

  • cut: Extract fields from text using byte positions.
  • awk: Advanced text processing and field extraction.
  • sed: Stream editor for text manipulation.