Linux system functions

In linux, the system function is implemented as a system function: www.2cto.com [cpp] # include & lt; sys/wait. h & gt; # include & lt; errno. h & gt; # include & lt; unistd. h & gt; intsystem (constchar * prop string) {pid_tpid
In linux, the system function is implemented as a system function: www.2cto.com [cpp] # include # Include # Include Int system (const char * character string) {pid_t pid; int status; if (character string = NULL) // return (1) directly when the system accepts the command as NULL ); if (pid = fork () <0) // fork a sub-process {status =-1;} else if (pid = 0) // the sub-process starts a program to replace itself. {execl ("/bin/sh", "sh", "-c", character string, (char *) 0); // call shell, the path of the shell is/bin/sh, and the rest is the parameter. the-c option tells the shell program to remove _ exit (127); // a command line parameter (here it is a running string) as command input .} else {while (waitpid (pid, & status, 0) <0) // the parent process waits for the self-process CONCLUSION. {if (errno! = EINTR) {status =-1; break ;}} return (status);} the neutron process is equivalent to calling:/bin/sh-c prepare string ----------- to execute the explain string command.