These signals are used to report various errors generated by an operation done by the program. They do not necessarily indicate a programming error in the program, but an error that prevents an operating system call from completing. The default action for all of them is to cause the process to terminate.
Broken pipe. If you use pipes or FIFOs, you have to design your application so that one process opens the pipe for reading before another starts writing. If the reading process never starts, or terminates unexpectedly, writing to the pipe or FIFO raises a
SIGPIPEsignal. IfSIGPIPEis blocked, handled or ignored, the offending call fails withEPIPEinstead.Pipes and FIFO special files are discussed in more detail in Pipes and FIFOs.
Another cause of
SIGPIPEis when you try to output to a socket that isn't connected. See Sending Data.
Resource lost. This signal is generated when you have an advisory lock on an NFS file, and the NFS server reboots and forgets about your lock.
On GNU/Hurd systems,
SIGLOSTis generated when any server program dies unexpectedly. It is usually fine to ignore the signal; whatever call was made to the server that died just returns an error.
CPU time limit exceeded. This signal is generated when the process exceeds its soft resource limit on CPU time. See Limits on Resources.
File size limit exceeded. This signal is generated when the process attempts to extend a file so it exceeds the process's soft resource limit on file size. See Limits on Resources.