Program 2

Program 2

#include<stdio.h>

#include<string.h>

#include<stdlib.h>

char str[50], pat[50], rep[50];

int start = 0, patfound = 0;

int lasts, lastp, lastr;

void replacepattern()

{

int i, j;

lastr = strlen(rep)-2;

if(lastp != lastr)

{

printf("\nInvalid length of replace string");

exit(0);

}

else

{

i = start;

for(j=0; j<=lastr; j++)

{

str[i] = rep[j];

i++;

}

}

return;

}

void findpattern()

{

int i, j, inmatch;

lasts = (strlen(str)) - 2;

lastp = (strlen(pat)) - 2;

int endmatch;

for(endmatch = lastp; endmatch<=lasts; endmatch++, start++)

{

if(str[endmatch] == pat[lastp])

{

inmatch = start;

j=0;

while(j<lastp)

{

if(str[inmatch] == pat[j])

{

inmatch++;

j++;

}

else

{

break;

}

}

if(j == lastp)

{

patfound = 1;

replacepattern();

}

}

}

return;

}

void main()

{

printf("\nEnter the main string(STR): ");

fgets(str, 50, stdin);

printf("\nEnter the pattern to be matched(PAT): ");

fgets(pat, 50, stdin);

printf("\nEnter the string to be replaced(REP): ");

fgets(rep, 50, stdin);

printf("\nThe string before pattern match is:\n %s", str);

findpattern();

if(patfound == 0)

printf("\nThe pattern is not found in the main string");

else

printf("\nThe string after pattern match and replace is: \n %s ", str);

};