> For the complete documentation index, see [llms.txt](https://eric-lo.gitbook.io/lab4-process/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://eric-lo.gitbook.io/lab4-process/process-execution/exec-family-execve.md).

# exec Family: execve

```c
/* Exec/execve.c */
#include <stdio.h>
#include <unistd.h>
int main(int argc,char *argv[]){ 
    char *env[] = {"LS_COLORS=fi=04;33;44",NULL}; 
    char *arg[] = {"ls","-l","--color",NULL}; 
    printf("Using *execve* to exec ls -l\n");  
    execve("/bin/ls",arg,env); 
    printf("Program Terminated\n");
    return 0;
}
```

`execve()` uses *filename*, *argument array* and *provided ENV* to execute the program.

```c
execve("/bin/ls",arg,env);
```

It only takes a filename to invoke the program, and it is searched in paths specified in `$PATH` in sequence.

The arguments are listed in an array of `char*` and passed to the function.

The new sets of environment variables are declared in an array of `char*` and passed to the program in the function. They can be used to change the behavior of the new program, for example, `ls` in this example.