Hands-On System Programming with Linux

The execle API

Now for the execle(3) API; its signature is:

int execle(const char *path, const char *arg, ...,char * const envp[]);

As before, the l in execle implies a long format variable argument list; the e implies that we can pass along an array of environment variables to the successor process.

The process environment consists of a set of <name>=<value> variable pairs. The environment is actually unique to each process and is stored within the process stack segment. You can see the entire list via either the printenv, env, or set commands (set is a shell built-in). Programmatically, use the extern char **environ to gain access to the process's environment.

By default, the successor will inherit the environment of the predecessor process. ...