Thread: copy strings in array

hi,

i have a string printed to by sprintf. i would like to: for every string printed, it copies the contents into the next element of a char array:

something like this (but this dosent work...

Code:

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

void addchars(char *sa[]){

int i;
char buf[100];

 for(i = 0; i  <= 3; ++i){
  sprintf(buf, "david %d\n",i);
  printf("%s", buf);
  strcpy(&sa[i],buf);
 }
}



int main() {

char *sa[25];


printf ("%s\n",sa[0]);
addchars(sa);
//printf("%s,%s,%s,%s,%s\n",sa[0],sa[1],sa[2],sa[3],sa[4]);
printf("%s",sa[0]);

return 0;


}

thanks

First off, you have to decide what this:

for every string printed, it copies the contents into the next element of a char array:

means. By definition, you cannot get a string into the next element of a char array -- the only thing you can get into the next element of a char array is a char.

Now, since you don't have any char arrays in your code, but do have char * arrays, I assume you mean that. In that case, sa[0], sa[1], ... are already your char *s that you would want to copy to, so adding & is fruitless. HOWEVER: currently sa[0], sa[1], etc. point to somewhere in New Jersey. You need to make them point to a string inside your computer, usually using malloc.

sorry :s

so: i have to make char * sa point to a space resevered by malloc?

-> is it even possible to get sa[0] = david 1, sa[1] = david 2 etc?

thanks for the quick response...

so like malloc(sizeof(sa)); ?

im not gonna lie anymore - i suck at string manipulation... i dont know how i would do that...

Originally Posted by davo666

sorry :s

so: i have to make char * sa point to a space resevered by malloc?

-> is it even possible to get sa[0] = david 1, sa[1] = david 2 etc?

thanks for the quick response...

You need to make each element of sa point to space reserved by malloc (not the array itself, but each string in the array).

no, i want to make a string with sprintf , then put that string into the first element of an array passed from the main function, then on the second iteration the second element.

thanks

@tabstop: ooooh so i initialise sa[i] = malloc(sizeofmystringfromsprintf); then make that space equal buf?

im going to try that

umm:

Code:

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

void addchars(char sa[]){

int i;
char buf[100];

 for(i = 0; i  <= 3; ++i){
  sprintf(buf, "david %d\n",i);
  printf("%s", buf);
  strcpy(sa[i],buf);
 }
}



int main() {

char sa[128][25];



addchars(sa);
printf("%s",sa[0]);

return 0;


}

this revised code dosent work...

Well, what the heck happened to "char *sa[]"? Edit: Even better yet, why not make it char sa[128][25]?

sorry, i used an old version of addchars, and copied the new main...

Code:

void addchars(char *sa[]){

int i;
char buf[100];

 for(i = 0; i  <= 3; ++i){
  sprintf(buf, "david %d\n",i);
  printf("%s", buf);
  strcpy(sa[i],buf);
 }
}



int main() {

char sa[128][25];



addchars(sa);
printf("%s",sa[0]);

return 0;


}

still doesn't work: test.c: In function 'main':
test.c:24: warning: passing argument 1 of 'addchars' from incompatible pointer type

thanks for all your help though

You'll need at least the 25 in the function declaration.

i still get the error msg though...