如何使用fgets查找.csv文件中是否存在此行？ （C）

Question

Hi I'm tyring to use fgets in a C program to see whether or not a name exists in a line in a .csv file. If it does, then it saves it in an array then returns it. Right now, it saves everything line from the .csv file and I'm not sure why.

C file:

void FindRecord(char *filename, char *name, char record[]) {

    char *temp = record; //temp save record

    FILE *q = fopen(filename, "r"); //check that ths inputed .csv file exists
    if (q == NULL ) { //if it doesn't, then print error message and exit
        printf("This .csv does not exist");
        exit(1); //terminate with error message
    }

    while(!feof(q)) { //while I'm not at the end of the file
        fgets(temp, 1000, q); //Reads a line @ a time
        for (int i = 0; i < 1000; i++) {
            if(temp[i] == *name) {
                record[i] = temp[i];
                name++;
            }
        }
        printf("%s", record);
    }
    fclose(q);   
}

.csv file:

Kevin, 123-456-7890
Sally, 213-435-6479
Megan, 415-336-8790

Right now whats happening when I run the program is that it returns the 3 lines. I want iso that if *name points to the name "Kevin" and it comes with temp, it'll just return: Kevin, 123-456-7890

Answer 1

Right now whats happening when I run the program is that it returns the 3 lines.

I don't see how that's possible. You have only one array in which to return a result. I could believe that your code prints all three lines, but it will return only the last.

I want iso that if *name points to the name "Kevin" and it comes with temp , it'll just return: Kevin, 123-456-7890

Well, your code has several problems in that regard. Among the most significant are:

• Although it performs some character-by-character comparisons, it has no code anywhere to reject lines that fail to match.

• It sets temp to point to the same array as record , and then reads each line into that array. This will overwrite that array even in the event that no match is found, and if a match is found on a line other than the last one read then the actual match will be lost.

• It modifies the name pointer as it attempts to match, with no mechanism for resetting it in the event of a partial match.

• When trying to match the name, it blithely scans past the , delimiter in the input line and, if it comes to them, the string terminators in the name and the input string.

• while (!feof(file)) is always wrong .