pclose - close pipe stream

Syntax	#include <stdio.h> int pclose(FILE *stream);
Description	pclose() closes the named stream that was opened by popen(), waits for the command started by popen() to terminate, and returns its exit status. However, if the exit status is unavailable to pclose(), then pclose() returns -1 and sets errno to ECHILD to report the situation. This may occur if the application has already obtained the exit status by one of the following functions: wait() waitpid() with a pid argument less than or equal to 0 or equal to the process ID of the command interpreter. In any case, pclose() will not return before the child process created by popen() has terminated. If the command interpreter cannot be executed, the child exit status returned by pclose() will be the same as if the command interpreter had terminated using exit(127) or _exit(127).
Return val.	Exit status of the command interpreter
		if successful.
	-1	if stream was not created by popen().
Errors	pclose() will fail if:
	ECHILD	The exit status of the child process could not be determined.
	Extension
	EINVAL	An attempt was made to access a BS2000 file. (End)
Notes	pclose() is executed only for POSIX files.
See also	fork(), popen(), wait(), waitpid(), stdio.h.