CSC209H1 Lecture Notes - C Dynamic Memory Allocation, .Bss, Compile Time
Document Summary
User: test b: 5. 250000: size of struct user is 16: Double pointers: most frequently used is for array of strings. Declare an int, compiler reserves 4 bytes. Declare an array of 4 ints, compiler reserves 16 bytes. 4 bytes int x = 2; int a[4]; int *b; int main() { Symbol table: main 0x804837c . text f9 x 0x8049588 . data 04. 0x8049688 . bss 04 a 0x804968c . bss 10: variables declared outside any functions are global variables. Things can happen to these variables and can"t easily follow the path of where the variables change sources of error. Better to put inside main functions: program nm prints out all the symbols of an executable. Shows which memory segments these symbols are found in. Even main has an address in the code component of the memory region. Dynamic memory allocation in c: memory is reserved in an unused slot in the heap via malloc void *malloc(size_t size);
