How to cut, translate, and join text columns in Linux

Lightweight text tools: cut pulls out columns, tr transforms characters, paste joins files column-wise.

# Cut fields 1 and 3 (colon-separated)
cut -d: -f1,3 /etc/passwd

# Cut a character range
cut -c1-10 <file>

# Translate lowercase to uppercase
tr 'a-z' 'A-Z' < <file>

# Delete carriage returns (DOS to Unix)
tr -d '\r' < dosfile > unixfile

# Join two files side by side
paste file1 file2