1. #include <stdlib.h>
  2. 	#include <stdio.h>
  3. 	#include <sys/types.h>
  4. 	#include <dirent.h>
  5. 	#include <errno.h>
  6. 	#include <ctype.h>
  7. 	#include <string.h>
  8.  
  9. 	int main (int argc, char *argv[]) {
  10.  
  11. 	DIR		*dir_pointer, *proc_dir;
  12. 	struct dirent	*dir_structure, *proc_struct;
  13.  
  14. 	FILE 		*fp;
  15.  
  16. 	int pid, ppid;
  17. 	char *pname;
  18. 	char pstate;
  19.  
  20. 	int i = 0;
  21.  
  22.  
  23. 	/*open directory stream*/
  24. 	dir_pointer = opendir("/proc/");
  25. 	printf("openning /proc/ dir\n");
  26.  
  27. 	char *digit_dir;	//all process id
  28. 	char **subdir;		//subdirectory for the processes
  29. 	subdir = (char**) calloc(sizeof(char**), 5000); 
  30. 	//store at least 5000 processes
  31. 	int j = 0; 
  32. 	/*reading reading files and directory*/
  33. 	while((dir_structure = readdir(dir_pointer)))
  34. 	{
  35. 		i++;
  36. 		digit_dir = (char*) (dir_structure->d_name);
  37.  
  38.  
  39. 		//store only directory that are process ID
  40. 		if(isdigit(dir_structure->d_name[0])){ 
  41. 		subdir[j]= (char*) dir_structure->d_name;
  42. 		j++;
  43. 		}
  44.  
  45. 	}
  46.  
  47. 	char *root = "/proc/";	
  48. 	char *file;
  49. 	char *new;  
  50.  
  51. 	printf("pid \t pname \t \t \t pstate \t ppid\n");
  52. 	while(*(subdir)!=NULL){ 	
  53.  
  54. 	new = (char *)calloc(strlen(root) + strlen(*subdir) + 1, sizeof(char));
  55. 		strcat(new, root);
  56. 		strcat(new, *subdir);
  57.  
  58.  
  59. 	file = (char *)calloc(strlen(new) + strlen("stats") + 1, sizeof(char));
  60. 	strcat(file, new);
  61. 	strcat(file, "/stat");
  62.  
  63.  
  64. 	fp = fopen(file,"r");
  65. 	if (fp == NULL) perror ("Error opening file");
  66. 		else {
  67.  
  68. 		pname = (char*) calloc(sizeof(char*),10); 
  69. 		fscanf(fp, "%d", &pid);
  70. 		fscanf(fp, "%s", pname);
  71. 		fscanf(fp, "%c", &pstate);
  72. 		fscanf(fp, "%d", &ppid);
  73.  
  74.  
  75. 		printf("%d\t%s\t\t%c\t\t\t\t%d\n",pid,pname,pstate,ppid); 
  76.  
  77.  
  78. 		fclose (fp);
  79. 		}
  80.  
  81.  
  82. 	*(subdir++);	
  83.  
  84. 	}
  85.  
  86.  
  87.  
  88.  
  89. 	return 0;
  90. 	}