Question

Me again 🙂
I need to break line if it is longer than 78 characters (including tab and spaces) and only in case it’s between patterns. Input looks like (digits may change):

— Pattern1 —
(tab here)2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . . . 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2
…
(tab here)2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 . . . 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
— Pattern2 —

and i need:

— Pattern1 —
(tab here)2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 .. (up to 78chars and then)&
(rest of previous line goes here,unless it’s still more then 78chars, becouse than again)&
(and so on and on until the end of the line) .. 2 2
next line also cutted to 78char lines
and again
— Pattern2 —

To achieve this i need to use scripting in bash 2.05

Answer 1

sed '/PATTERN1/,/PATTERN2/s/.\{78\}/&\n/g' ./infile

Input

$ cat ./infile
fasdflkjsakfsalfjasd
sadf
saf
saf
123456789A123456789B123456789C123456789D123456789E123456789F123456789G123456789H123456789I
sadf
sadfasfa
START
123456789A123456789B123456789C123456789D123456789E123456789F123456789G123456789H123456789I123456789J123456789K123456789L123456789M123456789123456789N123456789O123456789P
END
asf
sadfas
dfsad
fsad
fsad

Output

$ sed '/START/,/END/s/.\{78\}/&\n/g' ./infile
fasdflkjsakfsalfjasd
sadf
saf
saf
123456789A123456789B123456789C123456789D123456789E123456789F123456789G123456789H123456789I
sadf
sadfasfa
START
123456789A123456789B123456789C123456789D123456789E123456789F123456789G12345678
9H123456789I123456789J123456789K123456789L123456789M123456789123456789N1234567
89O123456789P
END
asf
sadfas
dfsad
fsad
fsad

Edit

If \n is not recognized by your version of sed. Try the following:

$ sed '/START/,/END/s/.\{78\}/&\
/g' ./infile

In case that’s not clear, after the ampersand, ‘&’, put a backslash to tell the shell you want to do line continuation then press ENTER to insert a literal newline. Finally, when on the next line, finish up the command with /g' ./infile