The C program compiled by GCC has a segment error.

The program is compiled and runs properly in VC 6.0,
A "segment error" occurs during compilation under GCC ",
Finally, it is found that the cycle is caused by the definition of Large variables,
I defined some variables in a while loop, for example:
While ()
{
Char A [50];
Char B [50];
Char C [20];
Memset (A, 0, 50 * sizeof (char ));
Memset (B, 0, 50 * sizeof (char ));
Memset (C, 0, 20 * sizeof (char ));
......
}

A segment error occurs during GCC compilation and running,
Generally, a segment error means that the accessed memory exceeds the memory space of the program provided by the system,
This value is usually stored by GDTR, which is a 48-bit register,
The 32-bit table stores the gdt table pointed to by it, and the last 13 BITs are saved to the corresponding gdt subscript,
The last three digits include whether the program is in the memory and the running level of the program in the CPU,
Gdt is a table in 64-bit units,
In this table, the code segment for running the program and the start address of the data segment are saved, and the corresponding
Segment limit, page exchange, program running level, memory granularity, and so on.
Once a program is accessed out of bounds, the CPU will generate corresponding exception protection,
Then segmentation fault appears.

The solution is to put variable definitions out of the loop. In fact, these most basic programming
Knowledge we have talked about as early as the code optimization of compilation principles. If you don't pay attention to it, problems may occur sometimes.

The code is changed to the following format, so there is no error in compiling and running.

Char A [50];
Char B [50];
Char C [20];
While ()
{
Memset (A, 0, 50 * sizeof (char ));
Memset (B, 0, 50 * sizeof (char ));
Memset (C, 0, 20 * sizeof (char ));
......
}