echo
display text output
TLDR
Print text
SYNOPSIS
echo [options] [string...]
DESCRIPTION
echo displays a line of text to standard output. It's one of the most basic and frequently used commands, essential for scripts, logging, and displaying information to users.
The command exists as both a shell built-in and standalone program.
PARAMETERS
-n
Don't output trailing newline-e
Enable interpretation of backslash escapes-E
Disable interpretation of backslash escapes (default)
ESCAPE SEQUENCES
(With -e flag):
\n - Newline
\t - Tab
\r - Carriage return
\a - Alert (bell)
\b - Backspace
\\\\ - Backslash
\\" - Double quote
\xHH - Hexadecimal byte
\0NNN - Octal byte
WORKFLOW
echo "Hello World"
# Multiple arguments
echo Hello World # Same as above
# Variables
name="Alice"
echo "Hello, $name"
# Without newline
echo -n "Enter name: "
read name
# Escape sequences
echo -e "Line 1\nLine 2\nLine 3"
echo -e "Name:\tJohn"
# Write to file
echo "log entry" > log.txt
# Append
echo "another entry" >> log.txt
# Empty line
echo
# Special characters
echo "Price: \$100"
REDIRECTION
echo "new content" > file.txt
# Append
echo "more content" >> file.txt
# To stderr
echo "error" >&2
# Discard output
echo "hidden" > /dev/null
COMMON USES
Scripts:
backup_files
echo "Backup complete"
echo $HOME
echo $USER
echo "echo 'Hello'" >> script.sh
chmod +x script.sh
echo "Here: $(pwd)"
SHELL BUILT-IN VS EXTERNAL
Most shells have echo as a built-in, which may behave differently than /bin/echo. Behavior varies between shells (bash, zsh, sh).
CAVEATS
Behavior differs between shells. -e and -E support varies. Backslash interpretation inconsistent. Prefer printf for portable scripts. Variable expansion happens before echo runs. Quotes affect word splitting.
HISTORY
echo has been part of Unix since Version 2 in 1972, though its behavior has varied across different Unix variants.