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  1. #include <stdio.h>
  2.  
  3. typedef int * int_ptr_t;
  4.  
  5. void f1(int_ptr_t ptr) {
  6.   printf("f1 ptr przed malloc: %p\n", ptr);
  7.   ptr = (int_ptr_t)malloc(sizeof(int));
  8.   printf("f1 ptr po malloc: %p\n", ptr);
  9. }
  10.  
  11. void f2(int_ptr_t *ptr) {
  12.   printf("f2 ptr przed malloc: %p\n", *ptr);
  13.   *ptr = (int_ptr_t)malloc(sizeof(int));
  14.   printf("f2 ptr po malloc: %p\n", *ptr);
  15. }
  16.  
  17. int main(void) {
  18.   int_ptr_t ptr = NULL;
  19.  
  20.   printf("main ptr: %p\n", ptr);
  21.  
  22.   f1(ptr);
  23.  
  24.   printf("main ptr po f1: %p\n", ptr);
  25.  
  26.   f2(&ptr);
  27.  
  28.   printf("main ptr po f2: %p\n", ptr);
  29.  
  30.   return 0;
  31. }
Success #stdin #stdout 0.02s 1852KB
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stdin
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Standard input is empty
stdout
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main ptr: (nil)
f1 ptr przed malloc: (nil)
f1 ptr po malloc: 0x882a008
main ptr po f1: (nil)
f2 ptr przed malloc: (nil)
f2 ptr po malloc: 0x882a018
main ptr po f2: 0x882a018
https://ideone.com/OJDmqh
language:
C (gcc 8.3)
created:
11 years ago
visibility:
public

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