How to solve exit code 139 error when reading from file on unix
SIGSEGV are not always thrown due to a root cause of memory access problems...
Perl throws a 139 on Unix usually because of file I/O. You might have accidentally deleted your input files.
TL;DR: Your program tried to access a memory location it had no permissions to access, so the operating system killed it.
First: The code "139" doesn't matter, forget about the number. Your program was terminated after "getting a SIGSEGV", or a signall regarding a segmentation violation. Read about what that means here:
What causes a SIGSEGV
(never mind that question is about C++, same idea.)
Now, why would this happen? You must be making some assumptions you shouldn't be. Looking at your code, it might be:
- Reading a very long string from the file which exceeds the bounds of the
loginInformationarray - and perhaps even the bounds of the memory region allocated to your program overall. - Scanning from an invalid-state/uninitialized/null file descriptor, as in @xuhdev's answer
- (Unlikely/impossible) Ignoring some error generated by one of the
fscanf()calls (you need to checkerrnoif a scan failed).
I think that covers it although maybe I missed something. Instead of speculating you can actually check what happened using a debugger on the core dump:
How do I analyze a program's core dump file with GDB when it has command-line parameters?
It means the program crashed before it exited. You need to debug the program. For example, you need to check whether the file is successfully opened after fopen.