How to check for tabulator in files?

Question

I would like to check a number of files for the existence of tab characters (ASCII 0x09) in them. (To assert that my sources are tab-free before committing them to repository.)

Preferably with standard tools. Of course, grep springs to mind, but apparently grep "\t" file.txt doesn't match...?!?

I am aware the answer is probably painfully simple, but I am at a loss.

Answer 1

Of course, grep springs to mind, but apparently grep "\t" file.txt doesn't match...?!?

That searches for the literal character t. To search for a tab literal with grep, your shell will usually have a literal-insertion method. For example, in bash, use grep $'\t' foo.txt.

Answer 2

try with $'\t' instead of \t

Answer 3

I don't believe grep understands the escape sequence \t. Try inserting a literal tab:

grep "<tab>" file.txt

Or, you can use awk instead.