C String operations

C Program to perform string operations

#include

#include

#include

#include

#include

int length(char str[]);

void reverse(char str[]);

int palindrome(char str[]);

void copy(char str1[], char str2[]);

int compare(char str1[], char str2[]);

void concat(char str1[], char str2[]);

void search(char str1[], char str2[]);

void count(char str1[]);

 void main()

{

   char a[100], b[100];

   int result, option;

   do

{

      printf("\n1.Length of a string");

      printf("\n2.Reverse the Given String");

      printf("\n3.Check for Palindrome");

      printf("\n4.Copy");

      printf("\n5.String Comparison");

      printf("\n6.String Concatenation");

      printf("\n7.String Searching");

      printf("\n8.Counting of Words,Characters & Special Characters");

      printf("\n9.Quit");

      printf("\n\nEnter Your Choice:");

      scanf("%d", &option);

      flushall();

      switch (option)

       {

      case 1:

         printf("\nEnter a String:");

         gets(a);

         result = length(a);

         printf("\nLength of %s=%d", a, result);

         printf("\nPress a Character");

         getch();

         break;

       case 2:

         printf("\nEnter a String:");

         gets(a);

         reverse(a);

         printf("\nResult=%s", a);

         printf("\nPress a Character");

         getch();

         break;

       case 3:

         printf("\n Enter a String:");

         gets(a);

         result = palindrome(a);

         if (result == 0)

            printf("\nNot a palindrome");

         else

            printf("\nA palindrome");

         printf("\nPress a Character");

         getch();

         break;

       case 4:

         printf("\nEnter a String:");

         gets(a);

         copy(b, a);

         printf("\nResult=%s", b);

         printf("\nPress a Character");

         getch();

         break;

       case 5:

         printf("\nEnter 1st string:");

         gets(a);

         printf("\nEnter 2nd string:");

         gets(b);

         result = compare(a, b);

         if (result == 0)

            printf("\nboth are same");

         else if (result > 0)

            printf("\n1st>2nd");

         else

            printf("\n1st<2nd span="">

         printf("\nPress a Character");

         getch();

         break;

       case 6:

         printf("\nEnter 1st string:");

         gets(a);

         printf("\nEnter 2nd string:");

         gets(b);

         concat(a, b);

         printf("\nresult=%s", a);

         printf("\nPress a Character");

         getch();

         break;

       case 7:

         printf("\nEnter 1st string:");

         gets(a);

         printf("\nEnter 2nd string:");

         gets(b);

         search(a, b);

         printf("\nPress a Character");

         getch();

         break;

       case 8:

         printf("\nEnter a string:");

         gets(a);

         count(a);

         printf("\nPress a Character");

         getch();

         break;

       default:

         printf("\nInvalid Choice:");

         break;

      }

    }

   while (option != 9);

}

int length(char str[])

{

   int i = 0;

   while (str[i] != '\0')

      i++;

   return (i);

}

void reverse(char str[])

 {

   int i, j;

   char temp;

   i = j = 0;

   while (str[j] != '\0')

      j++;

   j--;

   while (i < j)

   {

      temp = str[i];

      str[i] = str[j];

      str[j] = temp;

      i++;

      j--;

   }

} 

int palindrome(char str[])

{

   int i, j;

   i = j = 0;

   while (str[j] != '\0')

      j++;

   while (i < j)

   {

      if (str[i] != str[j - 1])

         return (0);

      i++;

      j--;

   }

   return (1);

} 

void copy(char str2[], char str1[])

{

   int i = 0;

   while (str1[i] != '\0')

   {

      str2[i] = str1[i];

      i++;

   }

   str2[i] = '\0';

} 

int compare(char str1[], char str2[])

{

   int i;

   i = 0;

   while (str1[i] != '\0') 

  {

      if (str1[i] > str2[i])

         return (1);

      if (str1[i] < str2[i])

         return (-1);

      i++;

   }

   return (0);

}

void concat(char str1[], char str2[])

{

   int i, j;

   i = 0;

   while (str1[i] != '\0')

      i++;

   for (j = 0; str2[j] != '\0'; i++, j++)

      str1[i] = str2[j];

   str1[i] = '\0';

}

void search(char str1[], char str2[])

{

   int i, j, lena, lenb;

   for (lena = 0; str1[lena] != '\0'; lena++)

   for (lenb = 0; str2[lenb] != '\0'; lenb++)

   for (i = 0; i <= lena - lenb + 1; i++)

  {

      for (j = 0; str1[i + j] == str2[j] && str2[j] != '\0'; j++);

      if (str2[j] == '\0')

         printf("\nString found at location : %d", i + 1);

   }

}

void count(char str[])

{

   int words = 0, characters = 0, spchar = 0, i;

   for (i = 0; str[i] != '\0'; i++)

   {

      if (isalnum(str[i]) && (i == 0 || !isalnum(str[i - 1])))

         words++;

      characters++;

      if (!isalnum(str[i]) && !isspace(str[i]))

         spchar++;

   }

   printf("\nNo of characters = %d", characters);

   printf("\nNo of special characters = %d", spchar);

   printf("\nNo of words = %d", words);

}

Output

1.Length of a string

2.Reverse the Given String

3.Check for Palindrome

4.Copy

5.String Comparison

6.String Concatenation

7.String Searching

8.Counting of Words,Characters & Special Characters

9.Quit

Enter Your Choice:1

Enter a String:pritesh

Length of pritesh=7

Press a Character