DRAFT lib: Add missing pipe prototype.

* include/unistd.h (pipe: New prototype.

include/unistd.h

@@ -82,6 +82,7 @@ int getpgid (pid_t pid);
 int isatty (int fd);
 int link (char const *old_name, char const *new_name);
 off_t lseek (int fd, off_t offset, int whence);
+int pipe (int filedes[2]);
 ssize_t read (int fd, void *buffer, size_t size);
 ssize_t readlink (char const *file_name, char *buffer, size_t size);
 #if __SBRK_CHAR_PTRDIFF

lib/stdio/pclose.c

@@ -26,6 +26,8 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 
+extern int *__ungetc_buf;
+
 int
 pclose (FILE *stream)
 {

lib/stdio/popen.c

@@ -23,6 +23,7 @@
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
@@ -34,8 +35,6 @@
 #define	SHELL_COMMAND_NAME "sh"
 #endif
 
-extern int *__ungetc_buf;
-
 FILE *
 popen (char const *command, char const *mode)
 {
@@ -61,7 +60,7 @@ popen (char const *command, char const *mode)
       // child
       int dup = (*mode == 'w'
                  ? dup2 (pipedes[STDIN], STDIN)
-                 : dup2 (pipedes[STDOUT], STDOUT))
+                 : dup2 (pipedes[STDOUT], STDOUT));
       if (dup < 0)
 	_exit (127);
 
@@ -109,6 +108,6 @@ popen (char const *command, char const *mode)
   // XXX misuse ungetc buffer for PID
   // XXX TODO: make proper FILE struct
   __ungetc_init ();
-  __ungetc_set (filedes, pidchild);
+  __ungetc_set (filedes, pid);
   return stream;
 }