Checking for a Blank Line When Reading From a File

So I have this text file which contains data about airports in the following format:

Code:

---

BUR Burbank
FAT Fresno
LGB Long Beach
LAX Los Angeles
MRY Monterey Peninsula
OAK Oakland
SMF Sacramento
SAN San Diego
SFO San Francisco
SJC San Jose
SBO Salina
SMO Santa Monica

  0  0  0  0 122  0  0  0  0  0 316  0
  0  0  0  0  0  0  0  0 321 455  0  0
  0  0  0 125  0  0  0  0 267  0  0  0
  0  0 125  0  0  50  0  0 250  0 370  0
122  0  0  0  0 259  0  0  0  0  0 119
  0  0  0  50 259  0  0 129  0  0  0  0
  0  0  0  0  0  0  0 111  0  0 125  0
  0  0  0  0  0 129 111  0  0  0  0  0
  0 321 267 250  0  0  0  0  0 190  0  0
  0 455  0  0  0  0  0  0 190  0  0  0
316  0  0 370  0  0 125  0  0  0  0 145
  0  0  0  0 119  0  0  0  0  0 145  0

---

The first part consists of codes and the names of the airport location, the second is a chart representing flight costs from one airport to the other.

Obviously, I cannot use the same logic to read both pieces of data, so I need to find a way to stop reading for names and codes once I reach the blank line that separates the two.

I was thinking that I could use the strcmp() function to compare the current line to the next line and continue to scan while the current line is greater than the next (the next only containing a new line character)

I have in mind something like:

Code:

---

char* current_line, *new_line;

//current_line = ?;
//new_line = ?;

while(strcmp(current_line, next_line) == 1)
{
    //read in data to structure I have already defined

}

---

Any and all feedback is appreciated :)

If you want to change your logic after encountering an empty line, then why not simply check whether the line is empty?

Simple.

//start
while(this line contains something)
do something
//the loop has finished so the blank line has been found
while(end of file not reached)
do something

FAQ > Get a line of text from the user/keyboard (C) - Cprogramming.com
Use fgets. Check the buffer to see if it contains only a newline (or alternately, only whitespace and a newline). Or fgets + sscanf, and see if sscanf returns what you expect.


Quzah.

so perhaps something along the lines of:

Code:

---

    FILE *fp1;
    char buf[BUFSIZ];
   
    //open file
   
    while(fgets(buf, sizeof(buf), fp1) != NULL)
    //do something

---

Maybe. How about giving it a try?


Quzah.

Ok I figured it out, it's working :biggrin:

Well, the first part that is.
This is just a test but everything works fine and there's no memory leak

Code:

---

void getData ()
{
    FILE *fp1;
    char buf[BUFSIZ];
    AIRPORT *temp;

    temp = createAirport();

    fp1 = fopen(FILE1, "r");
    if(!fp1)
    {
        printf("Error! Could not access file!");
        system("pause");
        exit(101);
    }
    //Get codes and names   
    while(strcmp(buf, "\n") != 0)
    {
        fgets(buf, sizeof(buf), fp1);
        //printf("%s\n", buf);
        sscanf(buf, "%4s%[^\n]s", temp->code, temp->name);
        printf("%s%s\n", temp->code, temp->name);
    }
   
    free(temp->name);
    free(temp);
    fclose(fp1);
    return;
}

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