#include <errno.h> /* errno */
#include <stdio.h> /* fprintf(3), stderr, "psops.c" */
#include <string.h> /* strerror(3) */
#include <sysexits.h> /* EX_OSERR */
#include <unistd.h> /* execvp(3) */
#include <sys/types.h> /* <sys/wait.h> */
#include <sys/wait.h> /* wait(2) */

#include "libpsargs.h" /* corresponding_arg(3), "psops.c" */

static char *program_name = "pspipe";

/* At the start of the loop argv[0] is { '[', '\0' } and file descriptor 0 is
 * the intended standard input */
int
f(char **argv){
	static int child;
	char **corr;
	int fd[2];
	int r;

	*(corr = corresponding_arg(argv)) = NULL;
	if(corr[1] != NULL){
		if(pipe(fd) != 0){
			fprintf(stderr,
				"%s: %s: %s\n",
				program_name, argv[1], strerror(errno)
			);
			return EX_OSERR;
		}
		if((r = fork()) == -1){
			fprintf(stderr, "%s: %s\n",
				program_name, strerror(errno)
			);
			return EX_OSERR;
		}
		if(r == 0)
			dup2(fd[0], 0);
		else
			dup2(fd[1], 1);
		close(fd[1]);
		close(fd[0]);
		if(r == 1)
			execvp(argv[1], argv+1);
	}

	argv = corr;
	return *++argv == NULL
		? WEXITSTATUS(child)
		: f(corr + 1);
}

#include "psops.c"