c - Linked List - data in previous nodes is being overwritten -

i have program puts directories in linked list , prints it. linked list getting messed nodes having same data. example, have folder "test' has 3 subfolders "good one", "jump", "sunday". output -> sunday sunday sunday.

on debug, first iteration of insert function, variable data in 1st node set "good one". address of root node pointer passed main. initially, startptr->data = "good one". after readdir executed, dir->d_name "jump".but startptr->data getting changed "jump". same happens 3rd "sunday" , nodes in list have data = "sunday".

not sure why happening. appreciate on this. here code:

#include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <dirent.h> #include <sys/stat.h>  /* self-referential structure */ struct listnode {     char *data; /* each listnode contains character */     struct listnode *nextptr; /* pointer next node */ }; /* end structure listnode */  typedef struct listnode listnode; /* synonym struct listnode */ typedef listnode *listnodeptr; /* synonym listnode* */  /* prototypes */ void insert( listnodeptr *sptr, char *value ); void printlist( listnodeptr currentptr );  int main( void ) {     listnodeptr startptr = null; /* there no nodes */      dir *d = null;     struct dirent *dir = null;      d = opendir ("/users/satish/documents/test");     if (d != null)     {         while ((dir = readdir (d)) != null)         {             /*printf("%s\n", dir->d_name);*/             if ( (strcmp(dir->d_name, ".")  == 0) || (strcmp(dir->d_name, "..")  == 0) )              {             }             else                 insert( &startptr, dir->d_name ); /* insert item in list */         }         closedir (d);     }     else         printf("%s/n", "couldn't open directory");      printlist( startptr );     printf( "end of run.\n" );     return 0; /* indicates successful termination */ } /* end main */  /* insert new value list in sorted order */ void insert( listnodeptr *sptr, char *value ) {     listnodeptr newptr = null; /* pointer new node */     listnodeptr previousptr = null; /*pointer previous node in list */     listnodeptr currentptr = null; /* pointer current node in list */      printf("%s\n", value);     newptr = malloc( sizeof( listnode ) ); /* create node */      if ( newptr != null )  /* space available */     {         newptr->data = value; /* place value in node */         newptr->nextptr = null; /* node not link node */          previousptr = null;         currentptr = *sptr;          if (currentptr == null)             *sptr = newptr;         else         {             while ( currentptr != null )              {                 previousptr = currentptr;                 currentptr = currentptr->nextptr;             }             previousptr->nextptr = newptr;             newptr->nextptr = null;         }     }        else     {         printf( "%c not inserted. no memory available.\n", value );     } /* end else */  } /* end function insert */   /* print list */ void printlist( listnodeptr currentptr ) {     /* if list empty */     if ( currentptr == null ) {         printf( "list empty.\n\n" );     } /* end if */     else {         printf( "the list is:\n" );          /* while not end of list */         while ( currentptr != null ) {             printf( "%s\n", currentptr->data );             currentptr = currentptr->nextptr;         } /* end while */          printf( "null\n\n" );     } /* end else */ } /* end function printlist */ 

output is:

the list is: sunday sunday sunday

in insert function pointing same address elements have allocate memory store name. see line 57 of code , add this:

    newptr = malloc( sizeof( listnode ) ); /* create node */    if ( newptr != null )  /* space available */    {     char *val=malloc((strlen(value)+1)*1);     strcpy(val,value);     newptr->data = val; /* place value in node */     newptr->nextptr = null;     .     .     .