Calling Operating System Commands

UNIX shell commands and executable programs can be called using the command "exec command ..." (see Section Calling Operating System Commands).

Examples:

<command> := ' ls -l ' displays the current directory

<command> := ' lp out ' prints the file 'out'

<command> := ' pgm1 > pgm1.lis' starts the program 'pgm1' writing the results to the file 'pgm1.lis'.