Thread: Problem with a loop

When I put the following code in a loop it will not write to the file. When I take it out of the loop it works fine (I realize that for now it is an infinite loop as that is part of the assignment). Any suggestions?

Code:

        while(!done) {
            printf("Enter line #%d: ",line_count++);
            if (fgets(user_line,MAX_LINE_LENGTH,stdin) == NULL) {
                fprintf(stderr,"Error reading user input: %s\n", strerror(errno));
            }
            if (fputs(user_line,memo_pntr) == EOF) {
                fprintf(stderr,"Error writing to file %s: %s\n",memo_file_path, strerror(errno));
            }
            
        }

Thanks!

Did you check stderr for errors?
Do you close the file (fclose()) after this loop? Maybe because the file is terminated violently (since it has infinite loop) the buffer isn't written to the file? Just a wild guess...

Yeah, I'm entering the loop and it closes afterwards (although with the current design it will never hit the close). I want to force the user to use cntrl-c to end for now.

Here is the whole code:

Code:

/*
 *CS306 Lab 5 lab5.c
 *Author: Chris Wiegman
 *Execute the memo program as specified in lab 5.
 *
 *Call as:
 * memo [MEMO_FILE]
*/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#define WAIT_TIME 10
#define MAX_LINE_LENGTH 100

void sigalrm_handler(int signal);
void sigint_handler(int signal);
void sigquit_handler(int signal);
void error_cleanup();

char *memo_file_path = NULL;
FILE *memo_pntr;

int main(int argc, char *argv[]) {

	int line_count = 1, done = 0;
        char user_line[MAX_LINE_LENGTH+1];

	switch (argc) {
		case 1:
			memo_file_path = "memo.text";
			break;
		case 2:
			memo_file_path = argv[1];
			break;
		default:
			fprintf(stderr,"Usage: memo [MEMO_FILE]\n");
			return EXIT_FAILURE;
			break;
	}

        if ((memo_pntr = fopen(memo_file_path, "w+")) == NULL) {
		fprintf(stderr,"Error opening file %s: %s\n",memo_file_path, strerror(errno));
		return EXIT_FAILURE;
	}

        while(!done) {
            printf("Enter line #%d: ",line_count++);
            if (fgets(user_line,MAX_LINE_LENGTH,stdin) == NULL) {
                fprintf(stderr,"Error reading user input: %s\n", strerror(errno));
            }
            if (fputs(user_line,memo_pntr) == EOF) {
                fprintf(stderr,"Error writing to file %s: %s\n",memo_file_path, strerror(errno));
            }
            
        }

        fclose(memo_pntr);

	return EXIT_SUCCESS;

}

void sigalrm_handler(int signal) {

}

void sigint_handler(int signal) {

}

void sigquit_handler(int signal) {

}

void error_cleanup() {

}

That was it. THANK YOU!