From 6af21e6a4f2251e71353562d5df7f376fdffc270 Mon Sep 17 00:00:00 2001 From: Freya Murphy Date: Tue, 25 Mar 2025 17:36:52 -0400 Subject: initial checkout from wrc --- user/progQ.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 user/progQ.c (limited to 'user/progQ.c') 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 + +/** +** 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! +} -- cgit v1.2.3-freya