Difference between revisions of "Echo"

From Linuxintro
imported>ThorstenStaerk
(Created page with "echo is a command to write something. By default this goes to stdout which by default goes to the console. Here is an example: tweedleburg:~ # echo "hello world" he...")
 
imported>ThorstenStaerk
 
(4 intermediate revisions by the same user not shown)
Line 1: Line 1:
echo is a [[command]] to write something. By default this goes to [[stdout]] which by default goes to the [[console]]. Here is an example:
+
echo is a [[command]] to write something. By default this goes to [[stdout]] which by default goes to the [http://simple.wikipedia.org/wiki/Command_Line_Interface console]. Here is an example:
 
  tweedleburg:~ # echo "hello world"
 
  tweedleburg:~ # echo "hello world"
 
  hello world
 
  hello world
Line 11: Line 11:
 
  tweedleburg:~ # cat file
 
  tweedleburg:~ # cat file
 
  hello world
 
  hello world
 +
 +
= Show all characters =
 +
To show all ascii characters you can use the following [[command]]:
 +
for l in $(seq 0 1 7); do for i in $(seq 0 1 7); do for n in $(seq 0 1 7); do \
 +
echo -en "\0${l}${i}${n}  "; done; done; done
 +
 +
= Show hexadecimal characters =
 +
echo -e "\x41"
 +
A
 +
 +
= See also =
 +
* [[sHell skripting tutorial]]

Latest revision as of 21:02, 6 January 2013

echo is a command to write something. By default this goes to stdout which by default goes to the console. Here is an example:

tweedleburg:~ # echo "hello world"
hello world

you can also output variables:

tweedleburg:~ # export name="Linus"
tweedleburg:~ # echo $name
Linus

for more info on this, see shell programming. As with every program that outputs text, you can redirect the output to a file like this:

tweedleburg:~ # echo "hello world" > file
tweedleburg:~ # cat file
hello world

Show all characters

To show all ascii characters you can use the following command:

for l in $(seq 0 1 7); do for i in $(seq 0 1 7); do for n in $(seq 0 1 7); do \
echo -en "\0${l}${i}${n}  "; done; done; done 

Show hexadecimal characters

echo -e "\x41"
A

See also