Linux command (like cat) to read a specified quantity of characters

Question

Is there a command like cat in linux which can return a specified quantity of characters from a file?

e.g., I have a text file like:

Hel         


        

Answer 1

You can use dd to extract arbitrary chunks of bytes.

For example,

dd skip=1234 count=5 bs=1

would copy bytes 1235 to 1239 from its input to its output, and discard the rest.

To just get the first five bytes from standard input, do:

dd count=5 bs=1

Note that, if you want to specify the input file name, dd has old-fashioned argument parsing, so you would do:

dd count=5 bs=1 if=filename

Note also that dd verbosely announces what it did, so to toss that away, do:

dd count=5 bs=1 2>&-

or

dd count=5 bs=1 2>/dev/null