Linux – Why are core dump files generated

coredumplinux

Sometimes when I run my code, a core dump file is generated when I terminate the program by Ctrl+\. The file name is of the form core.*. The program is not terminating abruptly, and there is no segmentation fault. I believe it is SIGQUIT and not SIGABRT or SIGSEGV. If I try Ctrl+C, or Ctrl+Z, then it is not generated.

Can anyone tell why it is generated only when Ctrl+\ is pressed? How can I avoid this core dump file from being generated? Is there any use for the core dumped file?

Best Answer

A process dumps core when it is terminated by the operating system due to a fault in the program. The most typical reason this occurs is because the program accessed an invalid pointer value. Given that you have a sporadic dump, it's likely that you are using an uninitialized pointer.

Can you post the code that is causing the fault? Other than vague generalizations it's hard to guess what's wrong without actually seeing code.

As for what a core dump actually is, check out this Wikipedia article:

http://en.wikipedia.org/wiki/Core_dump

Related Solutions

Macos – core dumps written on Mac

It seems they are suppressed by default. Running

$ ulimit -c unlimited

Will enable core dumps for the current terminal, and it will be placed in /cores as core.PID. When you open a new session, it will be set to the default value again.

Linux – How to change permissions for a folder and its subfolders/files in one step

The other answers are correct, in that chmod -R 755 will set these permissions to all files and subfolders in the tree. But why on earth would you want to? It might make sense for the directories, but why set the execute bit on all the files?

I suspect what you really want to do is set the directories to 755 and either leave the files alone or set them to 644. For this, you can use the find command. For example:

To change all the directories to 755 (drwxr-xr-x):

find /opt/lampp/htdocs -type d -exec chmod 755 {} \;

To change all the files to 644 (-rw-r--r--):

find /opt/lampp/htdocs -type f -exec chmod 644 {} \;

Some splainin': ^{(thanks @tobbez)}

chmod 755 {} specifies the command that will be executed by find for each directory
chmod 644 {} specifies the command that will be executed by find for each file
{} is replaced by the path
; the semicolon tells find that this is the end of the command it's supposed to execute
\; the semicolon is escaped, otherwise it would be interpreted by the shell instead of find

Best Answer

Related Solutions

Macos – core dumps written on Mac

Linux – How to change permissions for a folder and its subfolders/files in one step

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