#include<stdio.h>

int main()
{
    FILE *reading;
    FILE *writing;
    int condition,condition2;
    char input[100];
    char save[100];
    
    printf("Type a name to open for reading : ");
    scanf("%s",input);
    
    reading = fopen(input,"r"); /* OPENS the file name we typed above for reading */
    if(reading != NULL)
    {
        do
        {
            condition = fgets(save,30,reading);
            printf("\n%s",save);
        }while(condition != NULL);
    }
    else
    {
        printf("\nFile not found!!!!!\n");
    }
    getchar();
    getchar();
    fclose(reading);
    return(0);
}

in the do while loop the programme picks up 100 characters from the file...
but what if a file is not hundred characters...

then the programme is showing lines 2-3 times for completion of hundred characters...

if a file has 50 characters then the programme will show 50 characters 2 times for completion of 100 characters....
means it will print the programme 2 times....


what to do...
what to do to avoid this ....

do
        {
            condition = fgets(save,30,reading);
            printf("\n%s",save);
        }while(condition != NULL);

When you read the last part of the file, condition is not NULL.

It doesn't become NULL until you try to read after you've reached the end. Now you have an error. But you output the last stuff read again. Then the loop exits.

You need to figure out how to exit when you get the error, not after.

condition = fgets(save,30,reading);

fgets() returns a pointer to a string. condition is an int
declare condition as such: char *condition; save is a buffer of 100, but you only use 29 + the nul terminator '\0'
A better statement would be:

fgets( save, sizeof save, reading );

printf("\n%s",save); does add an extra return to each successful return of fgets() when displaying.

A possible better construct could be:

while ( fgets( save, sizeof save, reading ) != NULL )
    printf( "%s", save );

which will stop the loop if the file is empty or has reached the EOF, preventing printf() to display beyond that failure. And you don't need a variable named condition.

Edited 6 Years Ago by Aia: n/a

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