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 create and/or add input to a file: | 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# '''echo "This will overwrite whatever is in the file" > /root/testfile''' |
| − | samizdata# more /root/testfile | + | samizdata# '''more /root/testfile''' |
This will overwrite whatever is in the file | This will overwrite whatever is in the file | ||
| − | samizdata# echo "This will append to whatever is in the file" >> /root/testfile | + | samizdata# '''echo "This will append to whatever is in the file" >> /root/testfile''' |
| − | samizdata# more /root/testfile | + | samizdata# '''more /root/testfile''' |
This will overwrite whatever is in the file | This will overwrite whatever is in the file | ||
This will append to whatever is in the file | This will append to whatever is in the file | ||
Latest revision as of 12:51, 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.
