*String to String[] to *String

how can I copy a string like *String to a string like String[]? and vice-versa?

thanks!

strcpy

*String ---> String[]

Code:

---

#include<stdio.h>
#include<string.h>

main(void)
{
  char *String1 = "Program";
  int len = strlen(String1);
 
  char String2[len];
 
  strcpy(String2,String1);
 
  printf("%s = %s", String1,String2);
 
  getchar();
  return(0);
       
}

---

String[] ---> *String

Code:

---

#include<stdio.h>
#include<string.h>

main(void)
{
  char String1[] = "Program";
 
  char *String2; 
 
  strcpy(String2,String1);
 
  printf("%s = %s", String1,String2);
 
  getchar();
  return(0);
       
}

---

thanks... but I have a little problem here.

I will only know the *String after few lines of code... so I can't know the lenght of this when I declare the strings... is possible to change the size after declare? so how can I do that?

thanks again!

So use dynamic memory allocation method. Once you know the length of the array do

Code:

---

char *str;

str = malloc( sizeof char * len+1);

---

FYI: If you still need increase the size use realloc function . I case if you wanted to increase the size in the future.

EDIT: You need one more byte for null as well.
ssharish2005

don't forget to check for failure and to free it when you're done.

but this is a pointer right?

I'm like this:

Code:

---

char *String;
char NewStr[];


do some lines of code than I get *String;

len = strlen(String);

NewStr[] = malloc( sizeof char * len); // can I do that?

---

well, I need to read/copy char by char of this string to another, but seams that I can't do it like this:

Code:

---


char *String; //I can't change this!
char *NewStr;
                  while (String[j] != '}'){
                          NewStr[i] = String[j];
                          i++;j++;
                  }

---

so I think if *NewStr was a NewStr[] will work... or am I wrong?

thanks again!

NewStr[] is an array with an undetermined number of elements. It won't take a value returned from malloc. You'll need a pointer for that.

hmmm... so how I get the same result as the loop below using pointers?

Code:

---

char *String;
char *NewStr;
                  while (String[j] != '}'){
                          NewStr[i] = String[j];
                          i++;j++;
                  }

---

thanks again!

but you stilll need a malloc

http://www.cprogramming.com/tutorial/c/lesson6.html

Your also not allocating enough room for the null terminator :)

ok, I need do a malloc... but about my loop? is right?

is just because I do not alloc/free mem that didn't work? or what I did isn't possible to do with pointers like I did? or BOTH???

thanks again!

remove everything, then I'm trying part by part... but I'm stuck in the first one.

any of what you post worked.

Code:

---

/*
 =================
 CM_LoadEntityString
 =================
*/
static void CM_LoadEntityString (const byte *data, const lump_t *l){

        char        *game = Cvar_VariableString("fs_game"); // declare game - Hajas
        FILE        *f, *g;
        int                i, j, Tam, TamNew;
        int                PA, PB, PC, PD, PL, Num, Espaco, Aspas;
        char        *p = NULL, *ori = NULL, *HStr = NULL, *NewStr = NULL, *FinalStr = NULL;
        char        *PartA = NULL, *PartB = NULL, *PartC = NULL, *PartD = NULL;


        cm_numEntityChars = l->fileLen;
        if (cm_numEntityChars < 1)
                return;
        if (cm_numEntityChars > MAX_MAP_ENTSTRING)
                Com_Error(ERR_DROP, "CM_LoadMap: map '%s' has too large entity lump", cm_map);

        cm_entityString = Hunk_Alloc(cm_numEntityChars + 1);
        memcpy(cm_entityString, data + l->fileOfs, cm_numEntityChars);

        f = fopen ("entityORI.cfg", "wb");
        fprintf(f, "%s\n", cm_entityString);
        fclose(f);

        //if (!Q_stricmp(game, "arena")){
                // do string manipulation over cm_entityString
                *NewStr = 0;
                *FinalStr = 0;
                Tam = strlen(cm_entityString);
                HStr = malloc(sizeof cm_entityString);
                strcpy(HStr, cm_entityString); // copy the original string to mine
 
        g = fopen ("entityALT.cfg", "wb");
        fprintf(g, "%s\n", HStr);
        fclose(g);
        free(HStr);
        //}
}

---

abort the game....

I tryed these lines too:

Code:

---

HStr = malloc(sizeof (cm_entityString));
HStr = malloc(sizeof char * cm_entityString);
HStr = malloc(Tam);
HStr  = Hunk_Alloc(sizeof(cm_entityString));

---

nothing works... I'm doing nothing aside copy the string, why is not working?

Code:

---

ptr = malloc(sizeof(type) * elements);

---

You also don't check the result of your malloc, you assume it succeeds and continue on... malloc returns a NULL pointer on failure.

try strdup();