long -> hex i C

en long fylder nærmere 32 eller 64 bit

Ja, en blunder - ellers er der jo kun plads til 16 tal :-)

Men det må stadig være et eller andet med at dele det op i 4-bit-klumper hvis man skal konvertere mest effektivt ?

int main() { printf(\"%d\\n\", sizeof(long)); }
returnerede 4 på min dunk ihvertfald ...

returnerer sizeof antallet af bits ?

nej antal bytes

men du kan bare gange med 8 så har du antal bits

ok, så er vi jo også oppe på 32 bit

Men er der nogen der har mod på konverteringen ?

Jeg kan give dig et eksempel i Java :-)

Har ingen C++ kompiler på min maskine

Det skal helst være i C. Java kunne jeg godt selv klare, men jeg har aldrig programmeret noget i C og har intet at slå op i.

(Helst ikke C++ heller)

Det her burde kunne bruges :

/* ITOA.C: This program converts integers of various
* sizes to strings in various radixes.
*/

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

void main( void )
{
  char buffer[20];
  int  i = 3445;
  long l = -344115L;
  unsigned long ul = 1234567890UL;

  _itoa( i, buffer, 10 );
  printf( \"String of integer %d (radix 10): %s\\n\", i, buffer );
  _itoa( i, buffer, 16 );
  printf( \"String of integer %d (radix 16): 0x%s\\n\", i, buffer );
  _itoa( i, buffer, 2  );
  printf( \"String of integer %d (radix 2): %s\\n\", i, buffer );

  _ltoa( l, buffer, 16 );
  printf( \"String of long int %ld (radix 16): 0x%s\\n\", l,
                                                    buffer );

  _ultoa( ul, buffer, 16 );
  printf( \"String of unsigned long %lu (radix 16): 0x%s\\n\", ul,
                                                    buffer );
}


Output

String of integer 3445 (radix 10): 3445
String of integer 3445 (radix 16): 0xd75
String of integer 3445 (radix 2): 110101110101
String of long int -344115 (radix 16): 0xfffabfcd
String of unsigned long 1234567890 (radix 16): 0x499602d2

#include <stdio.h>

er det ikke en C++ inklude fil ?

du kan bruge enten \"printf()\" eller \"sprintf()\"
Den første printer diretke til consol vinduet hvis det altså bare er et simpelt kommandolinje program. Hvis du har vinduer bør du nok brug sprintf() som afleverer resultatet i en streng.

f.eks.

char s[40];
long tal= 255;
sprintf(s, \"Her er tallet i hex: %X\", tal);

Så skulle s gerne indeholde
\"Her er tallet i hex: FF\"

Du kan selfølgelig også undlade min liodet intelligente tekst og så blot skrive:
sprintf(s, \"%X\", tal);

Du kan slå printf og sprintf op i hjælpen eller hvis du har en bog om C. De kan formattere tekst på alle mulige måder, meget nyttige....

disky >> #include <stdio.h> skulle være en c ting. Ekspemlet er dog ikke testet, men taget fra en c hjælpefil...

Hvad med noget i denne retning?

int
main()
{
    long int l = 1234567;
    short int n;

    for(n=3;n>=0;n--)
        printf(\"%x \", ((unsigned char *)&l)[n]);
    printf(\"\\n\");
}

Min oventående kommentar var faktisk et svar og klart den letteste måde.
Husk at inkludere stdio.h filen som høre til Ansi C og derfor altid vil være tilgængelig uanset compiler...

mlutken: hmm, det lader til at jeg ikke kan se skoven for bare træer :) Fuck en omvej jeg gik .... :)

--> mlutken

Dit ser nemmest ud, men jeg kan ikke se hvor konverteringen sker. Hvorfor printer den det ikke ud som en long ?

Jeg har ikke ritigt noget sted at slå op med mindre det er indbygget i linux, men jeg har bestilt en bog, som snart skulle komme.

Jeg skal nok bruge printf da der ikke er nogen grafik overhovedet.

printf(\"Her er tallet i hex: %X\", tal);

printer direkte til kommandovinduet som du har startet programmet fra... virker umiddelbart i linux. Hemmeligheden ligger i i %X det store X fortæller printf at den skal konvertere argumentet til hex. Du kan skrive %-et-eller-andet lige så mange gange du vil og så bare supplere med argumenter til sidst, men se nedenfor... der er en del eksempler...

Måske kan du skrive \"man printf\" i din shell og få man siderne på printf, men ellers får du lidt her fra Microsofts hjælpefiler vedrørende C:


printf, wprintf
Print formatted output to the standard output stream.

int printf( const char *format [, argument]... );

int wprintf( const wchar_t *format [, argument]... );

Routine Required Header Compatibility
printf <stdio.h> ANSI, Win 95, Win NT
wprintf <stdio.h> or <wchar.h> ANSI, Win 95, Win NT


For additional compatibility information, see Compatibility in the Introduction.


Return Value

Each of these functions returns the number of characters printed, or a negative value if an error occurs.

Parameters

format

Format control

argument

Optional arguments

Remarks

The printf function formats and prints a series of characters and values to the standard output stream, stdout. If arguments follow the format string, the format string must contain specifications that determine the output format for the arguments. printf and fprintf behave identically except that printf writes output to stdout rather than to a destination of type FILE.

wprintf is a wide-character version of printf; format is a wide-character string. wprintf and printf behave identically otherwise.

Generic-Text Routine Mappings

TCHAR.H Routine  _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined
_tprintf printf printf wprintf


The format argument consists of ordinary characters, escape sequences, and (if arguments follow format) format specifications. The ordinary characters and escape sequences are copied to stdout in order of their appearance. For example, the line

printf(\"Line one\\n\\t\\tLine two\\n\");

produces the output

Line one
        Line two

Format specifications always begin with a percent sign (%) and are read left to right. When printf encounters the first format specification (if any), it converts the value of the first argument after format and outputs it accordingly. The second format specification causes the second argument to be converted and output, and so on. If there are more arguments than there are format specifications, the extra arguments are ignored. The results are undefined if there are not enough arguments for all the format specifications.

Example

/* PRINTF.C: This program uses the printf and wprintf functions
* to produce formatted output.
*/

#include <stdio.h>

void main( void )
{
  char  ch = \'h\', *string = \"computer\";
  int    count = -9234;
  double fp = 251.7366;
  wchar_t wch = L\'w\', *wstring = L\"Unicode\";

  /* Display integers. */
  printf( \"Integer formats:\\n\"
          \"\\tDecimal: %d  Justified: %.6d  Unsigned: %u\\n\",
          count, count, count, count );

  printf( \"Decimal %d as:\\n\\tHex: %Xh  C hex: 0x%x  Octal: %o\\n\",
            count, count, count, count );

  /* Display in different radixes. */
  printf( \"Digits 10 equal:\\n\\tHex: %i  Octal: %i  Decimal: %i\\n\",
            0x10, 010, 10 );

  /* Display characters. */

  printf(\"Characters in field (1):\\n%10c%5hc%5C%5lc\\n\", ch, ch, wch, wch);
  wprintf(L\"Characters in field (2):\\n%10C%5hc%5c%5lc\\n\", ch, ch, wch, wch);

  /* Display strings. */

  printf(\"Strings in field (1):\\n%25s\\n%25.4hs\\n\\t%S%25.3ls\\n\",
  string, string, wstring, wstring);
  wprintf(L\"Strings in field (2):\\n%25S\\n%25.4hs\\n\\t%s%25.3ls\\n\",
      string, string, wstring, wstring);

  /* Display real numbers. */
  printf( \"Real numbers:\\n\\t%f %.2f %e %E\\n\", fp, fp, fp, fp );

  /* Display pointer. */
  printf( \"\\nAddress as:\\t%p\\n\", &count);

  /* Count characters printed. */
  printf( \"\\nDisplay to here:\\n\" );
  printf( \"1234567890123456%n78901234567890\\n\", &count );
  printf( \"\\tNumber displayed: %d\\n\\n\", count );
}


Output

Integer formats:
  Decimal: -9234  Justified: -009234  Unsigned: 4294958062
Decimal -9234 as:
  Hex: FFFFDBEEh  C hex: 0xffffdbee  Octal: 37777755756
Digits 10 equal:
  Hex: 16  Octal: 8  Decimal: 10
Characters in field (1):
        h    h    w    w
Characters in field (2):
        h    h    w    w
Strings in field (1):
                computer
                    comp
  Unicode                      Uni
Strings in field (2):
                computer
                    comp
  Unicode                      Uni
Real numbers:
  251.736600 251.74 2.517366e+002 2.517366E+002

Address as:  0012FFAC

Display to here:
123456789012345678901234567890
  Number displayed: 16


Floating-Point Support Routines |  Stream I/O Routines |  Locale Routines

See Also  fopen, fprintf, scanf, sprintf, vprintf Functions

---------------------------
Og de forskellige format specifies...
--------------------------------
printf Type Field Characters
The type character is the only required format field ; it appears after any optional format fields. The type character determines whether the associated argument is interpreted as a character, string, or number. The types C and S, and the behavior of  c and s with printf functions, are Microsoft extensions and are not ANSI-compatible.

Table R.3  printf Type Field Characters

Character Type Output Format
c int or wint_t When used with printf functions, specifies a single-byte character; when used with wprintf functions, specifies a wide character.
C int or wint_t When used with printf functions, specifies a wide character; when used with wprintf functions, specifies a single-byte character.
d int Signed decimal integer.
i int  Signed decimal integer.
o int  Unsigned octal integer.
u int  Unsigned decimal integer.
x int Unsigned hexadecimal integer, using “abcdef.”
X int Unsigned hexadecimal integer, using “ABCDEF.”
e  double Signed value having the form [ – ]d.dddd e [sign]ddd where d is a single decimal digit, dddd is one or more decimal digits, ddd is exactly three decimal digits, and sign is + or –.
E double Identical to the e format except that E rather than e introduces the exponent.
f double Signed value having the form [ – ]dddd.dddd, where dddd is one or more decimal digits. The number of digits before the decimal point depends on the magnitude of the number, and the number of digits after the decimal point depends on the requested precision.
g double Signed value printed in f or e format, whichever is more compact for the given value and precision. The e format is used only when the exponent of the value is less than –4 or greater than or equal to the precision argument. Trailing zeros are truncated, and the decimal point appears only if one or more digits follow it.
G double Identical to the g format, except that E, rather than e, introduces the exponent (where appropriate).
n  Pointer to integer  Number of characters successfully written so far to the stream or buffer; this value is stored in the integer whose address is given as the argument.
p Pointer to void Prints the address pointed to by the argument in the form xxxx:yyyy where xxxx is the segment and yyyy is the offset, and the digits x and y are uppercase hexadecimal digits.
s String  When used with printf functions, specifies a single-byte–character string; when used with wprintf functions, specifies a wide-character string. Characters are printed up to the first null character or until the precision value is reached.
S String When used with printf functions, specifies a wide-character string; when used with wprintf functions, specifies a single-byte–character string. Characters are printed up to the first null character or until the precision value is reached.

Jamen så siger jeg tak for hjælpen.