Hi,

I would like to use grep to find files which contain NULL characters. I'm not sure how to represent the null character in the grep statement.

Could anyone help please?

Thanks!
Helen

What do you mean NULL character here??

Hi Mona,

I mean a Hex 00 character.

Cheers
Helen

I merged your threads. The trouble is that sed is using strings. My sed man page explicitly states: "It cannot edit binary files or files containing ASCII NUL (\0) characters or very long lines." Same with grep.

Hi,

Is it possible to use octal or hex in sed?

The problem I have is that I need to replace a NULL character (ie hex 00 or octal 000) with the string "NULL_CHARACTER".

tr would only replace the null character with one correstponding character. I would need to replace the null with a string of characters as above.

Many thanks
Helen

We managed to get around the problem in the end.

So for future reference:

we used od -b to turn the file into octal format. We then did a grep for " 000" in the file (note space before 000). This confirmed the file had a null character.

Just finding files with the null character was sufficient - we didn't look any further into replacing the null character.

Cheers
Helen