1 files changed, 1 insertions, 0 deletions
diff --git a/c/gbos.h b/c/gbos.h
index 2a99c0e..a0619cc 100644
--- a/c/gbos.h
+++ b/c/gbos.h
@@ -12,6 +12,7 @@ char         *getargs(void);              /* this program's argument string */
 char          readc(void);                /* one input byte, EOF at end    */
 void          sexit(unsigned char code);
 unsigned char getpid(void);
+unsigned char pipe(void);         /* -> read fd; write end is read+1 */
 
 /* helpers (c/libc.c) */
 void          putu(unsigned int n);              /* print decimal          */