How to Use cut Command in Bash: Syntax and Examples

Use the cut command in bash to extract specific sections from lines of text by specifying delimiters with -d and fields with -f, or by character positions with -c. For example, cut -d',' -f2 file.txt extracts the second field from comma-separated lines.

Syntax

The basic syntax of cut is:

• cut -d 'delimiter' -f fields [file]: Extract fields separated by a delimiter.
• cut -c positions [file]: Extract characters by position.
• cut [options]: Options control how text is sliced.

Explanation:

• -d: Specifies the delimiter character (default is tab).
• -f: Specifies which fields (columns) to extract, separated by commas or ranges.
• -c: Specifies character positions to extract.
• file: The input file; if omitted, cut reads from standard input.

bash

cut -d',' -f1,3 file.txt
cut -c1-5 file.txt

Example

This example shows how to extract the second field from a comma-separated file and how to extract the first 5 characters from each line.

bash

echo -e "name,age,city\nAlice,30,New York\nBob,25,Los Angeles" > data.csv
cut -d',' -f2 data.csv
cut -c1-5 data.csv

Output

age
30
25
name
Alice
Bob

Common Pitfalls

Common mistakes when using cut include:

• Not specifying the correct delimiter with -d, which defaults to tab.
• Using -f without -d on files that are not tab-separated.
• Mixing -f and -c options, which is not allowed.
• Expecting cut to handle multiple delimiters or complex patterns (it does not).

Wrong: cut -f2 file.csv on comma-separated file without -d','

Right: cut -d',' -f2 file.csv

bash

echo "a,b,c" | cut -f2
# Output is empty because default delimiter is tab

echo "a,b,c" | cut -d',' -f2
# Output: b

Output

b

Quick Reference

Option	Description
-d 'delimiter'	Set the field delimiter character
-f list	Select only these fields (columns)
-c list	Select only these character positions
--complement	Select all except the specified fields or characters
--help	Show help message

Key Takeaways

Always specify the correct delimiter with -d when using -f to extract fields.

Use -c to extract characters by position, and -f to extract fields by delimiter.

Do not mix -f and -c options in the same command.

cut reads from standard input if no file is given.

cut is simple and fast but only works with fixed delimiters and positions.