How to append parts of a string in a char array?-CodePudding

I need to split the string of n size and append in an array.

For example:

input:

abcdefghi
4

output:

[abcd,bcde,cdef,defg,efgh,fghi]

My code giving wrong answer:

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

int main()
{
  char str[] = "abcdefghi";
  char result[100]; 
  for(int i=0;i<strlen(str);i  ){
    strncat(result, str, str[i] 4);
  }
  printf("result: %s\n ", result);
}

My output:

abcdefgiabcdefgiabcdefgiabcdefgiabcdefgiabcdefgiabcdefgiabcdefgi

What mistake have I made??

CodePudding user response：

Would you please try the following:

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

int main()
{
    char str[] = "abcdefghi";
    char result[100];
    int n = 4;
    int i, j;
    char *p = result;                                   // pointer to the string to write the result

    *p   = '[';                                         // left bracket
    for (i = 0; i < strlen(str) - n   1; i  ) {         // scan over "str"
        for (j = i; j < i   n; j  ) {                   // each substrings
            *p   = str[j];                              // write the character
        }
        *p   = i == strlen(str) - n ? ']' : ',';        // write right bracket or a comma
    }
    *p   = '\0';                                        // terminate the string with a null character
    printf("result: %s\n", result);                     // show the result
    return 0;
}

Output:

result: [abcd,bcde,cdef,defg,efgh,fghi]

CodePudding user response：

Might this work for you?

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

int main ()
{
  char str[] = "abcdefghijklmno";
  char result[100][100]; 
  int nSplit = 4; //Split size
  int nLength = strlen (str); //Lenth of the string
  int nTotalString = nLength - nSplit; //total possibilities
  
  int nStrCount = 0;
  for (int i = 0; i <= nTotalString ; i   )
    {
      for (int j = 0; j < nSplit; j  )
           result[nStrCount][j] = str[i   j];
        nStrCount  ;
    }
    
  //print array
  printf ("result:[");
  for (int k = 0; k < nStrCount; k  )
    printf ("\"%s\" ", result[k]);
  printf ("]");
  return 0;
}