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Hi,

I have a text file as follows:

Line1....... 1111ABC
Line2....... 1134ABC
Line3....... 1149ABC
Line4....... 2140ABC

I just want to replace all ABC to DEF and increment all number by 1 if the number start with 11

The output file should be:

Line1....... 1112ABC
Line2....... 1135ABC
Line3....... 1150ABC
Line4....... 2140ABC

Can anyone tell me how to write a sed script to handle this case?

Thank

I'm no sed guru but i see a problem with the increment operation. Afik sed doesn't do maths. And it's not just a matter of replacing 1 with2, 2 with 3,... , there is the question of the carry on.
My way out of that would be to use a scripting langage with regular expressions.
Here is my suggestion in Python:

Code:

# type the following to run the pgm:

# python pgm_name.py inputfile_name



import sys, os, re, string



def parse_file(lines):

    #outfile= open(output_filename, 'w')

    for nextline in lines:

        #print nextline

        mtch= re.search("^ *(Line[0-9]\.+) *([0-9]+)(.+)", nextline)    

        if mtch :

            #print mtch.group(1),',',mtch.group(2),',',mtch.group(3)

            #print mtch.groups()

            if len(mtch.groups()) < 3 :

                  raise 'badly formatted line'

            m1=  mtch.group(1)

            m2=  int(mtch.group(2))

            if str(m2)[0]=='1':

                m2 +=1

            m3=  mtch.group(1)

            if m3 =='ABC':

                m3 = 'DEF'

            print m1,' ',m2,m3

            #outfile.write(m1,' ',m2,m3)    # uncomment here and above to write to a file



#===================================================================

def main():

        

    filename= sys.argv[1]

    try:

        f= open(filename, 'r')



        lines =f.readlines()

    except:

        st ="can't open file" + filename

        raise st

    parse_file(lines)



#---------------------------------------------------------------------------

#----------------------------------------------------------------------------



if __name__ == '__main__':

        main()



#----------------------------------------------------------------------------

OK, let's have some fun with shell scripting, another programming language that has regular expressions and that can do maths ;)

Code:

#!/bin/bash

sed 's/ABC/DEF/' ${1:?Missing argument, Usage: $0 file} | while line=$(line)

do

  number=$(expr "$line" : '[^1]*\(11[0-9]*\)DEF')

  prefix=$(expr "$number" : "\(.\{2\}\)")

  [[ "$prefix" = 11 ]] && echo $line | sed 's/'$number'/'$(expr $number + 1)'/' || echo $line

done