echo(C)

echo -- echo arguments

Syntax

echo [ -n ] [ arg ... ]

Description

The echo command writes its arguments separated by blanks and terminated by a new line on the standard output. The -n option prints a line without the newline; this is the same as using the ``\c'' escape sequence if it is placed at the end of the list of arguments. However, POSIX.2 and the X/Open CAE Specification, Commands and Utilities, Issue 4, 1992 do not support the -n option, so if you are using /bin/posix/echo rather than /bin/echo, the newline will always be printed. In this case, it may be suppressed using the printf(C) command.

echo also understands C-like escape conventions; beware of conflicts with the shell's use of ``\'':

\a

alert character (for example, ASCII BEL)

\b

backspace

\c

ignore all subsequent arguments, and do not output a newline

\f

form-feed

\n

new line

\r

carriage return

\t

tab

\v

vertical tab

\\

backslash

\0n

The 8-bit character whose ASCII code is a 0, 1, 2 or 3-digit octal number n. To prevent the argument being quoted literally, it must be escaped from the shell. For example:

echo '\065': echoes the number ``5''
echo \\0101: echoes the letter ``A''

For the octal equivalents of each character, see ascii(M).

The echo command is useful for producing diagnostics in command files and for sending known data into a pipe.

A version of this command is built into ksh(C) and sh(C).

Examples

When representing an 8-bit character by using the escape convention \0n, the octal number n must always be preceded by the digit zero (0).

For example, typing: echo "WARNING:\07" will print the phrase ``WARNING:'' and sound the ``bell'' on your terminal. The use of single (or double) quotes (or two backslashes) is required to protect the ``\'' that precedes the ``07''.

Limitations

The version of echo built into csh(C) only supports the escape sequences ``\c'' and ``\n''.

Standards conformance

echo is conformant with: