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cgcccodeblocks
Fenikso
Fenikso

Reputation: 9451

How to print 64-bit integer in GCC 4.4.1?

I am using Code::Blocks with GCC 4.4.1 and I seem to be unable to print 64-bit signed integers from my C-code.

This code:

long long longint;

longint = 0x1BCDEFABCDEFCDEF; /* 2003520930423229935 */
printf("Sizeof: %d-bit\n", sizeof(longint) * 8);     /* Correct */
printf("%llx\n", longint);                           /* Incorrect */
printf("%x%x\n", *(((int*)(&longint))+1), longint);  /* Correct */
printf("%lld\n", longint);                           /* Incorrect */

Produces output:

Sizeof: 64-bit
cdefcdef
1bcdefabcdefcdef
-839922193

64-bit arithmetic seems to work correctly:

longint -= 0x1000000000000000;
printf("%x%x\n", *(((int*)(&longint))+1), longint);

Gives:

bcdefabcdefcdef

Am I missing something?

Upvotes: 13

Views: 59232

Answers (5)

Amit Rai
Amit Rai

Reputation: 11

longint = 0x1BCDEFABCDEFCDEF; /* 2003520930423229935 */ you can print as-

printf("%llx", longint);

Upvotes: 1

dbrank0
dbrank0

Reputation: 9466

This is OS dependent. If you're doing this on just about any GCC that uses GLIBC, then %llx works.

However if you are using mingw compiler, then this uses Microsoft libraries, and you need to look into their documentation.

This changes your program to:

longint = 0x1BCDEFABCDEFCDEFLL; /* 2003520930423229935 */
printf("Sizeof: %d-bit\n", sizeof(longint) * 8);     /* Correct */
printf("%I64x\n", longint);                           /* Incorrect */
printf("%x%x\n", *(((int*)(&longint))+1), longint);  /* Correct */
printf("%I64d\n", longint);

Upvotes: 6

Fenikso
Fenikso

Reputation: 9451

Finally got it:

longint = 0x1BCDEFABCDEFCDEF; /* 2003520930423229935 */
printf("%I64d\n", longint);
printf("%I64x\n", longint);

Prints:

2003520930423229935
1bcdefabcdefcdef

Thanks @npclaudiu!

Upvotes: 0

Joachim Isaksson
Joachim Isaksson

Reputation: 180867

To (in C99 and up) portably print 64 bit integers, you should #include <inttypes.h> and use the C99 macros PRIx64 and PRId64. That would make your code;

printf("Sizeof: %d-bit\n", sizeof(longint) * 8);
printf("%" PRIx64 "\n", longint);
printf("%" PRId64 "\n", longint);

Edit: See this question for more examples.

Upvotes: 11

Pavan Manjunath
Pavan Manjunath

Reputation: 28525

See if %I64d helps you. %lld is fine for long long int but things get really different sometimes on Windows IDEs

Upvotes: 11

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