You are using temp
uninitialized in the following code:
char *temp;
...
while(endOfFile) {
fgets(temp,256,stdin);
...
This can have any side effect, since it most likely destroys your stack or parts of the heap memory. It could fail immediately (when calling the fgets()
function), it could fail later (as in your sample) or it could even run fine - maybe until you upgrade your OS, your compiler or anything else, or until you want to run the same executable on another machine. This is called undefined behaviour.
You need to allocate space for the temp
variable, not a pointer only. Use something like
char temp[256];
...
while(endOfFile) {
fgets(temp,256,stdin);
...
For more information, see the fgets()
documentation. The first parameter is a pointer to a char array - that is where fgets()
will store the bytes which have been read. In your code, you pass an uninitialized pointer which means that fgets()
will store the bytes to an undefined memory location - this is catched by the OS which terminates your application with a segmentation fault.
BTW: You should consider enabling pedantic warnings when compiling - I compiled with
g++ -Wall -pedantic -o list list.cpp
which gave me the following warning:
list.cpp: In function 'int readFile(int, char**)':
list.cpp:76:26: warning: 'temp' may be used uninitialized in this function [-Wuninitialized]