helps files in C

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helps files in C

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I need to create a program that writes a file of bytes , with the name that is entered, with a number and ask if that number is Mb or Gb and I already have the following code developed, although I think that is not the best way to do it because the file that is generated must contain "0xAA" which are 01, I really do not know how to write this type of data ...

with the for I have what string I print write "x" times to get to the desired way

for (i=0; i<=((529000)*numero*1000);i++)

instead of printing

fprintf(fichero, "%s","01");

but I would like to know how to print something similar to this:

  memset(*buffer, 0xaa, 1024);

or that is my question is the best way to print the "x" times the string so that the file that is created has the specified size?

c archivo

asked by Edú Arias 17.11.2016 в 22:15

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score 1 · Accepted Answer

What to write in the file, I do not understand what you want to say, but what if is simple:

In C, a string is a pointer to a string; by doing so

if( nombre1 == "mb" ) { ...

you're actually comparing 2 pointers , which will not match you.

You have to use the strcmp( ) function, which does just that, compare strings. It would be something like

if( ! strcmp( nombre1, "mb" ) )

or

if( strcmp( nombre1, "mb" ) == 0 )

strcmp( ) returns 0 if the strings are the same.

EDITO

I did not notice. The above will give you failure. You have done

char nombre1[2];

In C, strings are terminated with a byte 0 (which you do not see). Then, you need nombre1[3]; scanf () 'add the 0 automatically to the end of the string.

EDIT 2

To print, go well. You need to tune:

char Buffer[1001]; // Fíjate en que dejo espacio para el 0 final.
Buffer[1000] = 0; // Ponemos nosotros el 0. Los índices empiezan en 0 también.

memset( Buffer, 0xAA, 1000 ); // Descontamos el espacio extra para el 0.
// NO *Buffer. Solo Buffer.

fprintf( fichero, "%s", Buffer );

With fprintf( ... "%s" ... ) you indicate that you are going to print a text string ending in 0 . 0xAA no is zero, so we put a 0 at the end, and send it to print.

You can print the same buffer as many times as you want.