I have a file that has the following line in it: #define MM_VERSION_STR "3.0a4" I'm trying to find a way to set up a script that, when run, will change the value of "3.0a4" to "3.0a5" and when it is run the next time to "3.0a6" and so on...I'm thinking that awk and sed could do this but am not familiar with them. Any ideas??

Try this: awk '{ if ($2 ~ /MM_VERSION_STR/) printf "%s %s %s%d\"\n",$1,$2,substr($3,1,5),substr($3,6,1)+1 ; else print}' file

Or this: awk '/MM_VERSION_STR/ { sub(/\"/,"",$3) ; $0 = sprintf("%s %s \"%s%d\"",$1,$2,substr($3,1,4),substr($3,5)+1) } ; {print > ARGV[1] }' file ...which can even count beyond 10 ;) - and it modifies the file in place.

Replace /MM_VERSION_STR/ in the above by: $1 == "#define" && $2 == "MM_VERSION_STR" in case MM_VERSION_STR appears elsewhere in the same file.

Thanks Wolfbone! Still trying to figure this awk stuff out! I'm confused about if the field you want to replace is on another line. For example: resource 'tver' (1000) { "3.0a6" }; How would I change the "3.0a6" to "3.0a7" and so forth like above. Since the field is on the second line I'm not sure??