4: Handling Environment Variables with execle

pravjot

4: Handling Environment Variables with execle

Describe how the `execle()` system call is used to pass custom environment variables to a new process. What is the syntax and a typical use case?

gaurav133232

In execle, an environment variable array is provided, which provides a new environment for the process. The syntax of the call is like:

int execle(const char* path, const char* arg0...,(char*)0,char *const envp[])

A usecase for it could be defined as:

char *envp[] = {"USER=guest","PATH=/tmp",NULL};

execle("/bin/ls","ls","-l",(char*)0,envp);

This replaces the current process with the 'ls -l' command, searching for 'ls' in path with environment set to envp[].