C Program #12

/*A program that will search a line of given text for a particular pattern or substring. If the pattern is found it is to be replaced by another given pattern*/

#include<stdio.h>

#include<string.h>

int replace(char *,char[],char[],int,int,int,int);

int main()

{

char line[200],srch[15],rep[15];

int i,j,l_line,l_srch,l_rep,pos;

printf("\n Enter the line:");

gets(line);

l_line=strlen(line);

printf("\n Enter the pattern to be replaced:");

gets(srch);

l_srch=strlen(srch);

printf("\n Enter the pattern to be place:");

gets(rep);

l_rep=strlen(rep);

for(i=0;i<=(l_line-l_srch);i++)

            {

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

                                    if(line[i+j]==srch[j])

                                                continue;

                                    else

                                                break;

                                    if(j==l_srch)

                                                {

                                                pos=i;

                                                l_line=replace(line,srch,rep,pos,l_line,l_srch,l_rep);

                                                }

            }

printf("\n String after replacement:\n");

puts(line);

return 0;

}

int replace(char *line,char srch[],char rep[],int pos,int l_line,int l_srch,int l_rep)

{

int i,m=0;

            if(l_rep-l_srch>=0)

                        {

                        for(i=l_line-1;i>=(pos+l_srch);i--)

                                                            {

                                                            line[i+l_rep-l_srch]=line[i];

                                                            }

                        line[l_line+l_rep-l_srch]='\0';

                        for(i=pos,m=0;i<l_rep+pos;i++,m++)

                                    {line[i]=rep[m];}

                        return(strlen(line));

                        }

            else if(l_rep-l_srch<0)

                        {

                        for(i=(pos+l_srch),m=0;i<=l_line-1;i++,m++)

                                                            {

                                                            line[pos+l_rep+m]=line[i];

                                                            }

                        line[l_line-l_srch+l_rep]='\0';

                        for(i=pos,m=0;i<pos+l_rep;i++,m++)

                                    {line[i]=rep[m];}

                        return(strlen(line));

                        }

   else

   return(l_line);

}