user-0 提问: C调用外部可执行程序（交互式） 

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user: user-1
content: fork+exec

user: user-2
content: EXEC Section: Linux Programmer's Manual (3 ) Updated: 1993-11-29  --------------------------------------------------------------------------------    NAME execl, execlp, execle, execv, execvp - execute a file    SYNOPSIS #include <unistd.h>  extern char **environ;   int execl(const char *path, const char *arg, ...);  int execlp(const char *file, const char *arg, ...);  int execle(const char *path, const char *arg , ..., char * const envp[]);  int execv(const char *path, char *const argv[]);  int execvp(const char *file, char *const argv[]);     DESCRIPTION The exec family of functions replaces the current process image with a new process image. The functions described in this manual page are front-ends for the function execve(2). (See the manual page for execve for detailed information about the replacement of the current process.)  The initial argument for these functions is the pathname of a file which is to be executed.   The const char *arg and subsequent ellipses in the execl, execlp, and execle functions can be thought of as arg0, arg1, ..., argn. Together they describe a list of one or more pointers to null-terminated strings that represent the argument list available to the executed program. The first argument, by convention, should point to the file name associated with the file being executed. The list of arguments must be terminated by a NULL pointer, and, since these are variadic functions, this pointer must be cast (char *) NULL.   The execv and execvp functions provide an array of pointers to null-terminated strings that represent the argument list available to the new program. The first argument, by convention, should point to the file name associated with the file being executed. The array of pointers must be terminated by a NULL pointer.   The execle function also specifies the environment of the executed process by following the NULL pointer that terminates the list of arguments in the parameter list or the pointer to the argv array with an additional parameter. This additional parameter is an array of pointers to null-terminated strings and must be terminated by a NULL pointer. The other functions take the environment for the new process image from the external variable environ in the current process.   Some of these functions have special semantics.   The functions execlp and execvp will duplicate the actions of the shell in searching for an executable file if the specified file name does not contain a slash (/) character. The search path is the path specified in the environment by the PATH variable. If this variable isn't specified, the default path ``:/bin:/usr/bin'' is used. In addition, certain errors are treated specially.   If permission is denied for a file (the attempted execve returned EACCES), these functions will continue searching the rest of the search path. If no other file is found, however, they will return with the global variable errno set to EACCES.   If the header of a file isn't recognized (the attempted execve returned ENOEXEC), these functions will execute the shell with the path of the file as its first argument. (If this attempt fails, no further searching is done.)     RETURN VALUE If any of the exec functions returns, an error will have occurred. The return value is -1, and the global variable errno will be set to indicate the error.    FILES /bin/sh    ERRORS All of these functions may fail and set errno for any of the errors specified for the library function execve(2).    SEE ALSO sh(1), execve(2), fork(2), ptrace(2), environ(5)    COMPATIBILITY On some other systems the default path (used when the environment does not contain the variable PATH) has the current working directory listed after /bin and /usr/bin, as an anti-Trojan-horse measure. Linux uses here the traditional "current directory first" default path.  The behavior of execlp and execvp when errors occur while attempting to execute the file is historic practice, but has not traditionally been documented and is not specified by the POSIX standard. BSD (and possibly other systems) do an automatic sleep and retry if ETXTBSY is encountered. Linux treats it as a hard error and returns immediately.   Traditionally, the functions execlp and execvp ignored all errors except for the ones described above and ENOMEM and E2BIG, upon which they returned. They now return if any error other than the ones described above occurs.     CONFORMING TO execl, execv, execle, execlp and execvp conform to IEEE Std1003.1-88 (``POSIX.1'').  --------------------------------------------------------------------------------

user: user-3
content: 引用 楼主 fivedoumi 的回复:我想在LINUX系统中的C里边调用一个可执行程序 这个可执行程序是可交互的，即运行过程中会有多个用户提示，也可接受用户的多次输入。 我想在C里面模拟这个交互过程，有什么方法可以实现吗。  我查了一下，system()不可交互，而popen只能是单纯的输入或者输出重定向。 请问有其他可用的API吗？ 多线程，信号，共享内存，消息队列。

user: user-4
content: fork + excec