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-rw-r--r--user/progQ.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/user/progQ.c b/user/progQ.c
new file mode 100644
index 0000000..ecfcffc
--- /dev/null
+++ b/user/progQ.c
@@ -0,0 +1,43 @@
+#include <common.h>
+
+/**
+** User function Q: exit, write, bogus
+**
+** Reports itself, then tries to execute a bogus system call
+**
+** Invoked as: userQ x
+** where x is the ID character
+*/
+
+USERMAIN( main ) {
+ char ch = 'q'; // default character to print
+ char buf[128];
+
+ // process the command-line arguments
+ switch( argc ) {
+ case 2: ch = argv[1][0];
+ break;
+ default:
+ sprint( buf, "userQ: 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 );
+
+ // try something weird
+ bogus();
+
+ // should not have come back here!
+ sprint( buf, "!!!!! %c returned from bogus syscall!?!?!\n", ch );
+ cwrites( buf );
+
+ exit( 1 );
+
+ return( 42 ); // shut the compiler up!
+}