mirror of
https://xff.cz/git/u-boot/
synced 2025-10-30 01:53:48 +01:00
34e452dd02
Currently all shell command docs are put in the doc/usage root. Let's group them into cmd/ sub-directory. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
66 lines
988 B
ReStructuredText
66 lines
988 B
ReStructuredText
echo command
|
|
============
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
::
|
|
|
|
echo [-n] [args ...]
|
|
|
|
Description
|
|
-----------
|
|
|
|
The echo command prints its arguments to the console separated by spaces.
|
|
|
|
-n
|
|
Do not print a line feed after the last argument.
|
|
|
|
args
|
|
Arguments to be printed. The arguments are evaluated before being passed to
|
|
the command.
|
|
|
|
Examples
|
|
--------
|
|
|
|
Strings are parsed before the arguments are passed to the echo command:
|
|
|
|
::
|
|
|
|
=> echo "a" 'b' c
|
|
a b c
|
|
=>
|
|
|
|
Observe how variables included in strings are handled:
|
|
|
|
::
|
|
|
|
=> setenv var X; echo "a)" ${var} 'b)' '${var}' c) ${var}
|
|
a) X b) ${var} c) X
|
|
=>
|
|
|
|
|
|
-n suppresses the line feed:
|
|
|
|
::
|
|
|
|
=> echo -n 1 2 3; echo a b c
|
|
1 2 3a b c
|
|
=> echo -n 1 2 3
|
|
1 2 3=>
|
|
|
|
A more complex example:
|
|
|
|
::
|
|
|
|
=> for i in a b c; do for j in 1 2 3; do echo -n "${i}${j}, "; done; echo; done;
|
|
a1, a2, a3,
|
|
b1, b2, b3,
|
|
c1, c2, c3,
|
|
=>
|
|
|
|
Return value
|
|
------------
|
|
|
|
The return value $? is always set to 0 (true).
|