fork download
copy 
  1. /* ヘッダ */
  2. #include <stdlib.h>
  3. #include <stdio.h>
  4.  
  5. /* 課題 */
  6. void insert_str(const char *name, int row, int column, const char *str);
  7.  
  8. /* main() */
  9. int main(void){
  10. 	insert_str("data.txt", 4, 7, "test");
  11.  
  12. 	return 0;
  13. }
  14.  
  15. /* 課題 */
  16. void insert_str(const char *name, int row, int column, const char *str){
  17. 	/* 変数 */
  18. 	char *front;
  19. 	char *back;
  20. 	FILE *file_ptr;
  21. 	int count = 1;
  22. 	unsigned long int front_length, back_length;
  23.  
  24. 	/* エラー */
  25. 	file_ptr = fopen(name, "r");
  26. 	if(file_ptr == NULL){
  27. 		exit(1);
  28. 	}
  29. 	/* 指定行まで移動 */
  30. 	while(count < row){
  31. 		if(fgetc(file_ptr) == '\n'){
  32. 			++count;
  33. 		}
  34. 	}
  35. 	/* 指定列まで移動 */
  36. 	for(count = 0; count < column; ++count){
  37. 		fgetc(file_ptr);
  38. 	}
  39. 	/* 文字列の長さを保存 */
  40. 	front_length = ftell(file_ptr);
  41. 	fseek(file_ptr, 0, SEEK_END);
  42. 	back_length = ftell(file_ptr) - front_length;
  43. 	/* 文字列を保存 */
  44. 	front = (char *)malloc(sizeof(char) * (front_length + 1));
  45. 	back = (char *)malloc(sizeof(char) * (back_length + 1));
  46. 	fseek(file_ptr, 0, SEEK_SET);
  47. 	fread(front, sizeof(char), front_length, file_ptr);
  48. 	fread(back, sizeof(char), back_length, file_ptr);
  49. 	front[front_length] = '\0';
  50. 	back[back_length] = '\0';
  51.  
  52. 	fclose(file_ptr);
  53. 	/* 書き込み */
  54. 	file_ptr = fopen(name, "w");
  55. 	if(file_ptr == NULL){
  56. 		exit(1);
  57. 	}
  58. 	fprintf(file_ptr, "%s%s%s", front, str, back);
  59. 	fclose(file_ptr);
  60.  
  61. 	free(front);
  62. 	free(back);
  63. }
Runtime error #stdin #stdout 0s 2376KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
https://ideone.com/zpaN5a
language:
C (gcc 8.3)
created:
10 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!