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This article explains how to echo one or more tab characters when using Bash scripts.

Echo Tab Character in Bash Script

echoThe command is simple: it prints whatever is passed to the terminal. Normally, if you save a variable as:

example='         'testing

echo '['$example']'If you try to print out this variable using the command , you will get the following output.

[ testing]

This is not what we typed or saved into the variable. In the example above, we used the tab character twice, but we see only one space.

It should be noted that this behavior is not consistent across all shells. For example, running the same script in a zsh shell produces the following output, which is what we would expect.

[               testing]

Back to Bash scripting, we have several solutions.

Using the -e flag

-eThe -e flag enables interpretation of backslash escapes. If you were writing the same example above, you would write it as follows.

example='\t\t'testing
echo -e '['$example']'

This gives the output:

[               testing]

\tThe part represents the tab character. So since we want to introduce two tab characters, we write it as \t\t.

Once the -t flag is passed -e, \tthe symbol will be interpreted as a tab character and displayed as required.

If you do not use -ethe flag, as in the following case, then \tis read as a literal string and is not processed as a tab character.

example='\t\t'testing
echo '['$example']'

This gives the output:

[\t\ttesting]

Note that passing flag is not POSIX; therefore, this cannot be used portably, for example in a make that does not implement flag. Therefore, we will discuss some alternatives, including the almost universal printf.

Of course, this part is slightly different than when we started, as we're going to be ditching the echo altogether.

Use double quotes

This is arguably the simplest solution and requires no explanation other than the syntax. You would write the command as follows.

example='       'testing
echo "[$example]"

This will give the result:

[       testing]

Use printf instead

This is the most portable of the three solutions, and the most recommended. There are many implementations and versions of echo, but printf is basically the same.

Even if implemented separately everywhere, its implementation is very similar. We can see this because any variation of the above method will produce the same output when invoked with zsh, but different output when invoked with bash.

The syntax for using printf is defined as follows.

example='       'x
printf '%s\n' "[$example]"

This gives the output:

[       x]

As a general suggestion, as long as the desired output is simple text like hello, echothis will work fine, but for anything complex, using echomay become tricky as its behavior varies significantly between shells. In all such cases (special characters etc.), it is recommended to use instead printf.