Echo
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The simplest way to explain it is to see it in action: | The simplest way to explain it is to see it in action: | ||
| − | samizdata# echo "hello!" | + | samizdata# '''echo "hello!"''' |
hello! | hello! | ||
| − | It can also be used to add input to a file: | + | It can also be used to create and/or add input to a file: |
| − | samizdata# echo "This is | + | samizdata# '''echo "This will overwrite whatever is in the file" > /root/testfile''' |
| − | samizdata# more /root/testfile | + | samizdata# '''more /root/testfile''' |
| − | This is | + | This will overwrite whatever is in the file |
| − | samizdata# | + | samizdata# '''echo "This will append to whatever is in the file" >> /root/testfile''' |
| + | samizdata# '''more /root/testfile''' | ||
| + | This will overwrite whatever is in the file | ||
| + | This will append to whatever is in the file | ||
| + | |||
| + | See [[redirection]] for more on using > and >> and other operands to move data to and from [[standard input]], [[standard output]], files, and programs. | ||
| + | [[Category:System Commands]] | ||
Latest revision as of 13:51, 24 December 2004
echo repeats whatever has been given to it. From the manpage:
The echo utility writes any specified operands, separated by single blank
(` ') characters and followed by a newline (`\n') character, to the stan-
dard output.
The simplest way to explain it is to see it in action:
samizdata# echo "hello!" hello!
It can also be used to create and/or add input to a file:
samizdata# echo "This will overwrite whatever is in the file" > /root/testfile samizdata# more /root/testfile This will overwrite whatever is in the file samizdata# echo "This will append to whatever is in the file" >> /root/testfile samizdata# more /root/testfile This will overwrite whatever is in the file This will append to whatever is in the file
See redirection for more on using > and >> and other operands to move data to and from standard input, standard output, files, and programs.
