What you say, why? Why not! It’s a good example of how easy it is to do this sort of processing in Cobol. This program prompts for the name of an ASCII file ( in uppercase) to be convert, and the name of the converted file. It then checks to see if the file exists, and if not, exits the program. IF the uppercase file does exist, it converts all UPPERCASE characters found to lowercase, line-by-line, using inspect, and then writes them to the output file.
*> Program to convert a program from UPPERCASE to lowercase identification division. program-id. conv2lower. environment division. input-output section. file-control. select input-file assign to dynamic fname-uc organization is line sequential file status is upperFS. select output-file assign to dynamic fname-lc organization is line sequential file status is lowerFS. data division. file section. fd input-file. 01 sample-input pic x(80). fd output-file. 01 output-line pic x(80). working-storage section. 77 fname-uc pic x(30). 77 fname-lc pic x(30). 77 eof-switch pic 9 value 1. 77 upperFS pic xx. 77 lowerFS pic xx. 77 answer pic x. 01 input-area. 02 line1 pic x occurs 80 times. 01 output-area. 02 out-line pic x(80). procedure division. display "Input uppercase filename? ". accept fname-uc. open input input-file. if upperFS not = "00" then if upperFS = "35" then display "File not found: ", fname-uc stop run end-if end-if. display "Output lowercase filename? ". accept fname-lc. open output output-file. read input-file into input-area at end move zero to eof-switch end-read. perform proc-body until eof-switch is equal to zero. close input-file. close output-file. stop run. proc-body. inspect input-area converting "ABCDEFGHIJKLMNOPQRSTUVWXYZ" to "abcdefghijklmnopqrstuvwxyz". move input-area to out-line. write output-line from output-area. read input-file into input-area at end move zero to eof-switch end-read.