I have this code here to search a string in a file and display it. How can I edit this piece of code to make it possible to search just a part of this string? say, the file contains the author "dennis zill", if I search "zill" I want the code to display "dennis zill".

int searchauthor(FILE *ptr)    //searching starts
    {
        int save;
        char de;
        char in_name[30];
        int flag = 1;
    
        save = readbooks();
        ptr = fopen("books info.txt", "r");
        fflush(stdin);
        printf("\n Enter the name of the author: ");
        gets(in_name);
        printf("-------------------------------------------------");
    
        for(int i = 0; i < save; i  ){
            if(strcmpi(in_name, info[i].bauthor) == 0){
                printf("\n Book name: %s\n Price: %u\n Number of books available: %u\n Number of pages: %u\n-------------------------------------------------", info[i].bname, info[i].price, info[i].numavail, info[i].bpages);
                flag = 0;
            }
        }
    
        if (flag == 1){
            printf("\n Not found.\n Do you want to try another search [Y/N]? ");
            scanf("%c", &de);
            if(de == 'y' || de == 'Y'){
                system("cls");
                in_name[MAX] = reset(in_name);
                fclose(ptr);
                return 2;
            }
            else if(de == 'n' || de == 'N'){
                printf("\n You will be redirected to main menu");
                for(int k = 1; k <= 5; k  ){
                    Sleep(300);
                    printf(".");
                }
                system("cls");
                return 1;
            }
        }
    
        printf("\n\n Do you want to try another search [Y/N]? ");
        scanf("%c", &de);
    
        if (de == 'y' || de == 'Y') {
            system("cls");
            in_name[MAX] = reset(in_name);
            return 2;       //return 2 to case 3 to search again
        }
        else if (de == 'n' || de == 'N') {
            system("cls");
            printf("\n You will be redirected to main menu");
            for(int k = 1; k <= 5; k  ){
                Sleep(300);
                printf(".");
            }
            system("cls");
            return 1;
        }
    }  //searching ends

CodePudding user response：

The problem is the line:

if(strcmp(in_name, info[i].bauthor) == 0){

It will succeed only on a full match.

Rather that using strcmp use strstr (or its case-insensitive variant strcasestr() if it's available).

char *strstr(const char *haystack, const char *needle);

The haystack is the full authors name, needle the user's input. Function returns NULL on failure so it's enough to check if non-NULL was returned.

if(strstr(info[i].bauthor, in_name) != NULL){