NAME

gcore − Generate a core file from a Sprite process. 

SYNOPSIS

gcore [options] pid pid ...

OPTIONS

−o prefixGenerate the output file names by prepending the string prefix to each of the pids. 

−kKill the process after the core dump is produced. 

−s signalUse signal number signal to pause running process. 
 

DESCRIPTION

Gcore generates a snapshot of the current execution state of a Sprite process.  For historical reasons, these snapshot are referred to as core dumps or core files.  Core dumps can be used by the gdb debugger to examine the process’s state as if the debugger was attached to the process. 

Gcore takes as arguments one or more process ids and generates core dumps for each process in the file core.pid where pid is the specified process id.  The -o option allows a string other than "core" to be used to generate output file names.  If the -k option is specified, the processes specified will be sent a SIGKILL signal after the core dump is finished. 

Gcore reads the register state and memory image of a process by using the Sprite debugger interface (Proc_Debug.)  If the process is not already in the DEBUG state (see the ps command), gcore will send the process a SIGTRAP signal to force it into the DEBUG state.  This operation will fail if the user does not have permission to send signals to the process or the process has blocked, ignored, or has a handler installed for the SIGTRAP signal.  The -s option can be used to inform gcore to use a signal number other than 5 (SIGTRAP).  Other signals that may work are 4 (SIGILL), 8 (SIGFPE) and 11 (SIGSEGV).  Gcore restarts running process by sending them a SIGCONT after the dump is produced. 

WARNING

The signals used by gcore  to stop running processes can interrupt system calls such as read, select, or sleep, causing them to return an error status of EINTR.  Some programs may interpret the EINTR as an error and exit. 

KEYWORDS

gdb, coredump

Sprite version 1.0  —  February 05, 1989