HP gnu source-level debugger 5992-4701 manual Info handle is an alias for info signals

NOTE: Use caution if you disable all signals from certain processes. Disabling 'SIGTRAP' in your program may cause your program to hang.

HP-UX uses 'SIGTRAP' to communicate with the debugger. If you disable all signals from certain processes so that signals will be delivered to the right process, your program may hang when you try to debug it. This behavior occurs because if you disable 'SIGTRAP', the debugger no longer receives notification of events such as breakpoint hits and loading or unloading of shared libraries.

To prevent this problem:

Make certain you set this flag:

(gdb) set complain-if-sigtrap-disabled on

Also make certain the following warning was not emitted by the debugger before your program hung:

Warning: Thread %d (in process %d) has disabled SIGTRAPs. Debugging this thread is probably impossible.

If you do not want to see this message again, use: "set complain-if-sigtrap-disabled 0"

info signals, info handle Print a table of all the kinds of signals and how GDB has been told to handle each one. You can use this to see the signal numbers of all the defined types of signals.

info handle is an alias for info signals.

handle signal keywords... Change the way GDB handles signal signal. signal can be the number of a signal or its name (with or without the 'SIG' at the beginning). The keywords say what change to make.

The keywords allowed by the handle command can be abbreviated. Their full names are:

nostop GDB should not stop your program when this signal happens. It may still print a message telling you that the signal has come in.

stop GDB should stop your program when this signal happens. This implies the print keyword as well.

print GDB should print a message when this signal happens.

noprint GDB should not mention the occurrence of the signal at all. This implies the nostop keyword as well.

68 Stopping and Continuing