Command Line – Grabbing First [x] Characters from a String

command lineshelltext processing

If I have really long output from a command (single line) but I know I only want the first [x] (let's say 8) characters of the output, what's the easiest way to get that? There aren't any delimiters.

Best Answer

One way is to use cut:

 command | cut -c1-8

This will give you the first 8 characters of each line of output. Since cut is part of POSIX, it is likely to be on most Unices.

Related Solutions

Command-Line – How to Insert a Space Every Four Characters in a Long Line

Use sed as follows:

$ echo "foobarbazblargblurg" | sed 's/.\{4\}/& /g'
foob arba zbla rgbl urg

Linux Text Processing – Replace All Characters Except the First Four

With GNU Sed,

md5sum input.txt | sed 's/./x/5g'

This simply skips substituting the 4 first characters of the string and performs the substitution for all other characters.

A POSIX alternative with Awk (although there is probably something simpler),

md5sum xad | awk '{
  four=substr($0, 1, 4)
  rest=substr($0, 5)
  gsub(/./, "x", rest)
  print four, rest
}' OFS=""

Best Answer

Related Solutions

Command-Line – How to Insert a Space Every Four Characters in a Long Line

Linux Text Processing – Replace All Characters Except the First Four

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