CODEWITHSUNDEEP
cchar
Dan1676
Dan1676

Reputation: 1725

C Read a file line Max count

#include <stdio.h>
#include <stdlib.h>
int main ( int argc, char *argv[] )
{
//sets the number of lines ot be read  
char strline[10000]; 
// checks to see that there are only 2 entries in the argv by checking in argc
if ( argc != 2 )
    {
        printf( "ERROR. Enter a file name\n", argv[0] );
    }
    else 
    {
       //opens the file which was entered by the user as read only 
       FILE *infile = fopen( argv[1], "r");
        // covers a miss spelling of a file name or file doesn't exist
        if ( infile == 0 )
        {
            printf( "ERROR. Did you make a mistake in the spelling of the file or the File entered doesn't exist\n" );
        }
        else 
        {
            // File exists read lines, while not at the end of the file
while  (!feof(infile))
                {   
//Get next line to be printed up to 126 characters per a line
if(fgets(strline, 126, infile))
            {
                //print the current line (stored in strline)
printf("%s",strline);
            }
        }
    //closes the file
fclose( infile );
    return 0;        
    }
    }
}

On the 6th line (comment above) I have stated this is the maximum amount of lines the program can read. I was informed yesterday that this isn't the case.

Can someone explain to me what the code line actually means?

char strline[10000];

So from what people have being saying what setting it to 128 make more snese (126 for fgets and some room)

Upvotes: 0

Views: 2337

Answers (1)

AndersK
AndersK

Reputation: 36082

char strline[10000]; neans you have allocated a buffer that is 10,000 bytes long:

           +--------------...-+
strline -> |      10000       |
           +--------------...-+

if you wanted to allocate for 10,000 lines instead you would need something like this:

char* strline[10000]; // array of 10,000 pointers to strings

accessing lines would be to assign to each entry in the array

strline[0]
strline[1]
...
strline[10000]

like when a line is read you would need to allocate a buffer for the line and then point to it from strline

char* line = malloc( linelength + 1 );
fgets( line, linelength, fp );
strline[0] = line;

              +-------+
strline[0] -> | line  |
              +-------+

Upvotes: 3

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