Shell Script Learning 14 Shell echo command

Echo is an internal command of the shell that prints the specified string on the screen. Command format:

1. Echo Arg

You can use echo to achieve more complex output format control.

Show escape characters

1. echo "\"It is a test\ ""

The result will be:
"It is a test"

Double quotes can also be omitted.

Show variables

1. Name="OK"
2. echo "$name It is a test"

The result will be:
OK It is a test

The same double quotation marks can also be omitted.

If the variable is connected to another character, you need to use curly braces ({}):

1. Mouth=8
2. echo "${mouth}-1-2009"

The result will be:
8-1-2009

Show line breaks

1. echo "ok! \ n"
2. Echo "It is a test"

Output:
Ok!
It is a test

Show No Line breaks

1. echo "ok! \c"
2. Echo "It is a test"

Output:
Ok! It si a test

Show results redirected to file

1. Echo "It is a test" > MyFile

Output string AS-is

If you want to output the string as-is (without escaping), use single quotation marks. For example:

1. echo ' $name\ '

Show command Execution results

1. Echo ' Date '

The result will show the current date

As can be seen from the above, double quotes are dispensable, single quotes are mainly used in the original output.

Shell Script Learning 14 Shell echo command