Thread: tokenizing alphabetically

hey guys, finished off most of this code. I believe I should be using strcmp to compare the two newly tokenized strings and put the first alphabatized string first.

Need help with part 4
example input
this is a string

output
a
is
string
this

any help is greatly appreciated

Code:

#include <stdio.h>
#include <string.h>
  
void RecursiveReverse(const char *const sPtr);
  
int main()
{
    
  /*Part One*/
  char buffer1 [] = {'T','h','i','s',' ','i','s',' ','a',' ','l','o','o','p','\0'};
  char buffer2 [] = {"This is the second buffer"};
  char buffer3 [80];
  char buffer4 [100];
  char buffer5 [100];
  char *tokenptr;
//  char *tokenptr1;
  
  gets(buffer3);
  printf("\n%s\n", buffer1);
  printf("%s\n", buffer2);
  
  /*Part 2*/
  char *pb;
  pb = buffer3;
  
  while(*pb != '\0'){
    printf("%c", *pb);
    pb++;
  }
   
  printf("\n");
 
  /*Part Three*/
  printf("The line to print:\n");
  gets(buffer4);
  printf("The new line is:\n");
  RecursiveReverse(buffer4);
  printf("\n");
  
  /*Part 4*/
  printf("Please enter the string to be parsed:\n");
  gets(buffer5);
  printf("\n");
  tokenptr = strtok(buffer5, " ,");                     /*Begins tokenizing*/
  
  while(tokenptr != NULL){
    printf("%s\n", tokenptr);
    tokenptr = strtok(NULL, " ,");                      /*Gets next token*/
  }
  printf("\n");
//  while(tokenprt != NULL)
  
  return 0;
}
  
void RecursiveReverse(const char *const sPtr)
{ 
  if (sPtr[0] == '\0'){
    return;
  }
  else{
  RecursiveReverse(&sPtr[1]);
  
  putchar(sPtr[0]);
  }
}

I don't see any logic for sorting, but yes, strcmp(string1, string2) is what you want. the return from strcmp() will be 0 if the strings are equal, or the open end of the <, sign, will point toward the string that is greater.

strcmp(s1, s2) == 0, strings are equal
strcmp(s1, s2) < 0, means s2 is greater than s1
strcmp(s1, s2) > 0, means s1 is > s2.

The actual values strcmp() returns may differ from compiler to compiler, but always the above will be true.

thanks for the help.
How would I go about comparing the buffer5 strings?

Code:

 printf("Please enter the string to be parsed:\n");
  gets(buffer5);
  printf("\n");
  tokenptr = strtok(buffer5, " ,");                     /*Begins tokenizing*/
  
  while(tokenptr != NULL){
    printf("%s\n", tokenptr);
    tokenptr = strtok(NULL, " ,");

I guess what I mean is, I only put inputs into one string and it gets tokenized. How do I get
the program to compare two of the tokenized characters.?

i guess i am having problems understanding how to differentiate each string in buffer5 and knowing how to differentiate them.

how do i use strcmp for this?

Code:

 printf("Please enter the string to be parsed:\n");
  gets(buffer5);
  printf("\n");
  tokenptr = strtok(buffer5, " ,");                     /*Begins tokenizing*/
  
  while(tokenptr != NULL){
    printf("%s\n", tokenptr);
    tokenptr = strtok(NULL, " ,");

The strings have to be differentiated before you can use strcmp(). It has to be able to find the strings before it can make any comparison.

You have several buffers (char arrays). Can't you put a separate token into each of these buffers?

It's a klutzy work-around, but it could work for just a few tokens.

could I essentially do this:?

Code:

 printf("Please enter the string to be parsed:\n");
  gets(buffer5);
  printf("\n");
  
  tokenptr = strtok(buffer5, " ,;.");                   /*Begins tokenizing*/
    
  while(tokenptr != NULL){
    printf("%s\n", tokenptr);
    tokenptr = strtok(NULL, " ,;.");                    /*Gets next token*/
    }
  
  char *b[20];             /* Begins putting each tokenized string into a array b*/
  
  b[0] = strtok(buffer5, " ,;.");
  
  for(i = 1; i < 20; i++){       
    b[i] = strtok(NULL, " ,;.");
    b[i + 1] = strtok(NULL, " ,;.");
    }

putting the tokenized strings into the array b. I just cant seem to get it to work. I thought that having the base case on the outside was the way to go but it doesn't work. It only prints the first stored value.

k well, I am trying very hard to understand this. Here is another way I tried doing it.

Code:

char *b[20];
    
  b[0] = strtok(buffer5, " ,;.");
  
  for(i = 1; i < 20; i++){
    b[i] = strtok(NULL, " ,;.");
    }

just so i could

Code:

if(strncmp(b[i], b[i+1])==0)
printf("%s\n", b[i]);

but it seems to tell me segmentation fault core dumped

Okay, I now know what the problem is

Code:

  /*Part 4*/
  printf("Please enter the string to be parsed:\n");
  gets(buffer5);
  printf("\n");

  
char *b[20];
    
  b[0] = strtok(buffer5, " ,;.");
  
    for(i = 0; i < 2; i++){
    b[i+1] = strtok(NULL, " ,;.");
    printf("%s\n", b[i]);
    }

The red is the problem, it dumps it if I don't input 2 strings. How do I get around that?

When I put in two inputs works no problem
Sample Input:
asdf. asdf
Sample Output:
asdf
asdf

When i put in 1 input:
asdf
output:
a

a
Segmentation fault (core dumped)