1 files changed, 61 insertions, 0 deletions
diff --git a/user/progKL.c b/user/progKL.c
new file mode 100644
index 0000000..6bfb987
--- /dev/null
+++ b/user/progKL.c
@@ -0,0 +1,61 @@
+#include <common.h>
+
+/**
+** User function main #4:  exit, fork, exec, sleep, write
+**
+** Loops, spawning N copies of userX and sleeping between spawns.
+**
+** Invoked as:  main4  x  n
+**	 where x is the ID character
+**		   n is the iteration count (defaults to 5)
+*/
+
+USERMAIN( main ) {
+	int count = 5;			// default iteration count
+	char ch = '4';			// default character to print
+	int nap = 30;			// nap time
+	char msg2[] = "*4*";	// "error" message to print
+	char buf[32];
+
+	// process the command-line arguments
+	switch( argc ) {
+	case 3:	count = str2int( argv[2], 10 );
+			// FALL THROUGH
+	case 2:	ch = argv[1][0];
+			break;
+	default:
+			sprint( buf, "main4: argc %d, args: ", argc );
+			cwrites( buf );
+			for( int i = 0; i <= argc; ++i ) {
+				sprint( buf, " %s", argv[argc] ? argv[argc] : "(null)" );
+				cwrites( buf );
+			}
+			cwrites( "\n" );
+	}
+
+	// announce our presence
+	write( CHAN_SIO, &ch, 1 );
+
+	// argument vector for the processes we will spawn
+	char *arglist[] = { "userX", "X", buf, NULL };
+
+	for( int i = 0; i < count ; ++i ) {
+
+		write( CHAN_SIO, &ch, 1 );
+
+		// second argument to X is 100 plus the iteration number
+		sprint( buf, "%d", 100 + i );
+		int whom = spawn( ProgX, arglist );
+		if( whom < 0 ) {
+			swrites( msg2 );
+		} else {
+			write( CHAN_SIO, &ch, 1 );
+		}
+
+		sleep( SEC_TO_MS(nap) );
+	}
+
+	exit( 0 );
+
+	return( 42 );  // shut the compiler up!
+}