paste — Merge Lines Horizontally

Merge lines side by side — the horizontal counterpart to cat for combining columnar data from multiple sources.

Merge Files Column-Wise

Paste two files side by side — tab-delimited by default

paste names.txt scores.txt

Paste three files — each becomes a column

paste first.txt last.txt email.txt

Paste with a specific delimiter — comma-separated

paste -d',' names.txt scores.txt

Paste with colon delimiter — build /etc/passwd-style records

paste -d':' users.txt uids.txt shells.txt

Transpose a file — all lines become one line, tab-separated

paste -s names.txt

Transpose with comma delimiter — create a comma-separated list

paste -sd',' names.txt

Transpose multiple files — each file becomes one row

paste -s file1.txt file2.txt file3.txt

Join lines of a single file with a space — flatten to one line

paste -sd' ' input.txt

Rotating delimiter — alternates through characters in the delimiter string

# paste cycles through the delimiter characters:
paste -d',;:' f1.txt f2.txt f3.txt f4.txt
# Between f1-f2: comma, f2-f3: semicolon, f3-f4: colon

Pair lines with comma, then separate pairs with newline — every two lines joined

paste -d',\n' - - < data.txt

Group every 3 lines into one tab-delimited record

paste - - - < data.txt

Group every 4 lines with comma delimiter

paste -d',' - - - - < data.txt

Combine command output as columns without temp files

paste <(cut -d':' -f1 /etc/passwd) <(cut -d':' -f7 /etc/passwd)

Side-by-side comparison of two command outputs

paste <(df -h | awk '{print $1, $5}') <(df -h | awk '{print $6}')

Number lines — paste line numbers alongside content

paste <(seq $(wc -l < data.txt)) data.txt

Merge sorted and original — see what sort changed

paste <(cat data.txt) <(sort data.txt) | column -t -s$'\t'

Build a lookup table from two commands

paste <(getent passwd | cut -d: -f3) <(getent passwd | cut -d: -f1) | sort -n

Create a CSV from parallel arrays

paste -d',' <(printf '%s\n' host1 host2 host3) <(printf '%s\n' 192.168.1.10 192.168.1.11 192.168.1.12) <(printf '%s\n' up up down)

Add headers to pasted output

(echo -e "NAME\tSCORE\tGRADE"; paste names.txt scores.txt grades.txt) | column -t

Interleave a file with a separator — insert blank lines between records

paste -d'\n' data.txt /dev/null | head -20

Reshape single-column data into N columns — e.g., 3 columns from one list

paste - - - < long_list.txt

Create key=value pairs from alternating lines

paste -d'=' - - < alternating.txt
# Input:     Output:
# name       name=alice
# alice      age=30
# age
# 30

Combine paste with column for aligned output

paste <(lsblk -dno NAME) <(lsblk -dno SIZE) <(lsblk -dno TYPE) | column -t

Quick side-by-side diff alternative — compare two files visually

paste <(awk '{printf "%-40s", $0}' file1.txt) file2.txt