Linux / Unix Error Handling Commands/Functions.

Functions strerror() and strerror_r()

Returns a string describing the error code passed in the argument errnum.

errno - Number of last error

Set by system calls (or library functions) to indicate what went wrong.

Function perror()

Returns a message on the standard error output, describing the last error encountered during a call to a system or library function.

Function strsignal()

Returns a string describing the signal number passed in the argument sig.