count number of tab characters in linux

Use tr to discard everything except tabs, and then count:

< input-file tr -dc \\t | wc -c

bash unix csh grep

Bash uses a $'...' notation for specifying special characters:

grep -c $'\t' foo

bash unix csh grep

Use a perl regex (-P option) to grep tab characters.

So, to count the number of tab characters in a file:

grep -o -P '\t' foo | wc -l

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