add sys_printchar

userland/include/unistd.h

@@ -156,4 +156,6 @@ int execvp(const char *prog, char *const *args); /* calls execv */
 char *getcwd(char *buf, size_t buflen);          /* calls __getcwd */
 time_t time(time_t *seconds);                    /* calls __time */
 
+int printchar(char c);
+
 #endif /* _UNISTD_H_ */

userland/testbin/Makefile

@@ -8,7 +8,7 @@ TOP=../..
 SUBDIRS=add argtest badcall bigexec bigfile bigfork bigseek bloat conman \
 	crash ctest dirconc dirseek dirtest f_test factorial farm faulter \
 	filetest forkbomb forktest frack hash hog huge \
-	malloctest matmult multiexec palin parallelvm poisondisk psort \
+	malloctest matmult multiexec palin parallelvm poisondisk printchartest psort \
 	randcall redirect rmdirtest rmtest \
 	sbrktest schedpong sort sparsefile tail tictac triplehuge \
 	triplemat triplesort usemtest zero

userland/testbin/printchartest/Makefile

@@ -0,0 +1,11 @@
+# Makefile for printchartest
+
+TOP=../../..
+.include "$(TOP)/mk/os161.config.mk"
+
+PROG=printchartest
+SRCS=printchartest.c
+BINDIR=/testbin
+
+.include "$(TOP)/mk/os161.prog.mk"
+

userland/testbin/printchartest/printchartest.c

@@ -0,0 +1,17 @@
+#include <unistd.h>
+
+extern int printchar(char c);
+
+int main() {
+
+  printchar('C');
+  printchar('S');
+  printchar('E');
+  printchar('4');
+  printchar('0');
+  printchar('0');
+  printchar('1');
+  printchar('\n');
+
+  return 0;
+}