exec函数族 整理笔记

以ls -l为例

#include <unistd.h>

int execl(const char *path, const char *arg, ...);
int execlp(const char *file, const char *arg, ...);
int execl(const char *path, const char *arg, ..., char * const envp[]);
int execv(const char *path, char *const argv[]);
int execl(const char *file, char *const argv[]);
int execl(const char *path, char *const argv[], char * const envp[]);

①execl

execl(“/bin/ls”, “ls”, “-l”, NULL);

②execlp 在上面的基础上去掉了ls的路径/bin/

execlp(“ls”, “ls”, “-l”, NULL);

③execv 把”ls”, “-1”, NULL这些命令行参数通过指针数组str传给exec函数

char *str[] = {“ls”, “-l”, NULL};
execv(“/bin/ls”, str);

④execvp  在上面的基础上去掉了ls的路径/bin/

char *str[] = {“ls”, “-l”, NULL};
execvp(“ls”, str);

⑤execle

char *arrEnv[] = {“PATH=/bin:/usr/bin”, “TERM=console”, NULL};
execle(“/bin/ls”, “ls”, “-l”, NULL, arrEnv);

⑥execve

char *str[] = {“ls”, “-l”, NULL};
char *arrEnv[] = {“PATH=/bin:/usr/bin”, “TERM=console”, NULL};
execve(“/bin/ls”, str, arrEnv);