bashgcccommand-line

gcc from command line with define -D coming as output of another program

I want to compile a program which includes a define -D. The define is not fixed, but is the output of another program genRandom. In other words, the genRandom program outputs a random 10 characters string. I want to use that to be a define of the first program. I am using Linux with Bash as shell. In effect I want something like:

gcc main.c -DVAL=<output of genRandom>

The end result is the define is randomly generated at compile time.

Solution

  • The bash syntax for incorporating the output of a command into a command line is `command` or $(command). So gcc main.c -DVAL=$(genRandom) would do what you ask.