Segmentation error in C while allocation memory -


i total begginer @ c programming , trying write program reads value of "stat" file in /proc/. works first few entries, returns "segmentation error (core dumped)". far found out error has allocation of memory, cant seem find way fix it. code far is:

char* readfile(char* filename) {  file *fp;     struct stat buf;     fp=fopen(filename,"r");     stat(filename,&buf);     char *string = malloc(buf.st_size);     char *s;     while(!feof(fp))     {             s=malloc(1024);             fgets(s,1024,fp);             s[strlen(s)-1]='\0';             strcat(string,s);     }     return string;  }  char* readstat(char* path, int statnumber) {    char* str = malloc(sizeof(readfile(path)));   str = readfile(path);   char * pch = malloc(sizeof(str));   char * vals;   pch = strtok (str," ");   int = 1;   while (pch != null)   {   if(i == statnumber)         vals = pch;     pch = strtok(null, " ");     i++;   }   return vals;  }

1) the

s=malloc(1024);

should not while should oitside while loop , before while.

and free before leaving function:

free(s);

2) add

string[0] = '\0';

just after 

char *string = malloc(buf.st_size);

otherwise strcat not work properly

3) not need allocate memory str pointer because readfile function did 

char* str = malloc(sizeof(readfile(path)));

just replaced with

char* str;

4) , replace

char * pch = malloc(sizeof(str));

by

char * pch = str;

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