1 files changed, 104 insertions, 0 deletions
diff --git a/user/progI.c b/user/progI.c
new file mode 100644
index 0000000..c37eddf
--- /dev/null
+++ b/user/progI.c
@@ -0,0 +1,104 @@
+#include <common.h>
+
+#ifndef MAX_CHILDREN
+#define MAX_CHILDREN	50
+#endif
+
+/**
+** User function I:  exit, fork, exec, kill, sleep, waitpid, write
+**
+** Reports, then loops spawing userW, sleeps, kills two children, then
+** loops checking the status of all its children
+**
+** Invoked as:  userI [ x [ n ] ]
+**	 where x is the ID character (defaults to 'i')
+**		   n is the number of children to spawn (defaults to 5)
+*/
+
+USERMAIN( main ) {
+	int count = 5;	  // default child count
+	char ch = 'i';	  // default character to print
+	int nap = 5;	  // nap time
+	char buf[128];
+	char ch2[] = "*?*";
+	uint_t children[MAX_CHILDREN];
+	int nkids = 0;
+
+	// process the command-line arguments
+	switch( argc ) {
+	case 3:	count = str2int( argv[2], 10 );
+			// FALL THROUGH
+	case 2:	ch = argv[1][0];
+			break;
+	case 1:	// just use the defaults
+			break;
+	default:
+			sprint( buf, "userI: 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" );
+	}
+
+	// secondary output (for indicating errors)
+	ch2[1] = ch;
+
+	// announce our presence
+	write( CHAN_SIO, &ch, 1 );
+
+	// set up the argument vector
+	// we run:	userW 10 5
+
+	char *argsw[] = { "userW", "W", "10", "5", NULL };
+
+	for( int i = 0; i < count; ++i ) {
+		int whom = spawn( ProgW, argsw );
+		if( whom < 0 ) {
+			swrites( ch2 );
+		} else {
+			swritech( ch );
+			children[nkids++] = whom;
+		}
+	}
+
+	// let the children start
+	sleep( SEC_TO_MS(nap) );
+
+	// kill two of them
+	int32_t status = kill( children[1] );
+	if( status ) {
+		sprint( buf, "!! %c: kill(%d) status %d\n", ch, children[1], status );
+		cwrites( buf );
+		children[1] = -42;
+	}
+	status = kill( children[3] );
+	if( status ) {
+		sprint( buf, "!! %c: kill(%d) status %d\n", ch, children[3], status );
+		cwrites( buf );
+		children[3] = -42;
+	}
+
+	// collect child information
+	while( 1 ) {
+		int n = waitpid( 0, NULL );
+		if( n == E_NO_CHILDREN ) {
+			// all done!
+			break;
+		}
+		for( int i = 0; i < count; ++i ) {
+			if( children[i] == n ) {
+				sprint( buf, "== %c: child %d (%d)\n", ch, i, children[i] );
+				cwrites( buf );
+			}
+		}
+		sleep( SEC_TO_MS(nap) );
+	};
+
+	// let init() clean up after us!
+
+	exit( 0 );
+
+	return( 42 );  // shut the compiler up!
+}