I have a large data file in text format and I want to convert it to csv by specifying each column length.
number of columns = 5
column length
[4
GNU awk (gawk) supports this directly with FIELDWIDTHS, e.g.:
FIELDWIDTHS
gawk '$1=$1' FIELDWIDTHS='4 2 5 1 1' OFS=, infile
Output:
aasd,fh,90135,1,2 ajsh,dj, 2445,d,f