[SOLVED] Convert hex string to int in kernel

yoavf · 03-13-2011, 05:03 AM

Hello,
How to convert an hex string to integer inside a device driver, w/o wrinting my own utility.
I see that sscanf, strtol are undef.

Thanks

bastl · 03-13-2011, 09:00 AM

Hello.
It sounds like you are a beginner, so tell us what you want to do, what the problem is.

yoavf · 03-13-2011, 10:42 AM

I am a beginner with device drivers

I am trying to convert hex string to integer using some lib utility, instead of writing it myself.
sscanf, strtol failed to pass compilation.
Then I tried atoi, which returns 0.

Here is the relevant input, code, and log:
Input (dispatch is a process that calls device drive):
/usr/htdr/bin/dispatch 0x35 0x0b 0x130 1 U1400.1B1.019DF02-P1-C3

Code:
int mapRemoteCommand (char *arg, char *rasSimulatedArg, int *op) {

int subCommand;
char *op_str;
char *subCommand_str;

WRITE_LOG("110313 L901 cpssdd mapRemoteCommand start: arg = %s\n", arg, NULL);
/* Remove Remote Command OP from input string */
if (NULL == strtok (arg, space_delimiter)) {
WRITE_LOG("110309 L1704 cpssdd: op= %d; arg= %s\n", op, arg);
WRITE_LOG("OPeration=%d failed on remote Lpar \n", op, NULL);
return 0;
}

op_str = strtok (NULL, space_delimiter);
/* 110313 Does not work: sscanf (op_str, "%x", op); */
/* 110313 Does not work: *op = strtol( op_str, NULL, 0); */
*op = atoi(op_str);
WRITE_LOG("110313 L912 cpssdd mapRemoteCommand: RAS op=%d; op_str = %s\n", *op, op_str);
/* *op is the 2nd field in Remote command - after Remote Command OP */

if (*op <= OS_IOCTL_MAX_CMDS) {
/* RAS command */
subCommand_str = strtok (NULL, space_delimiter);
/* 110313 Does not work: sscanf (subCommand_str,"%x",&subCommand); */
/* 110313 Does not work: *op = strtol( subCommand_str, NULL, 0); */
subCommand = atoi(subCommand_str);
WRITE_LOG("110313 L921 cpssdd mapRemoteCommand: op= %d; op_str = %s\n", *op, subCommand_str);

((OsIoctlRas *) (arg))->header.subCommand = subCommand; /* Subcommand is in the same position for all RAS commands types */
}
return 1; /* DEBUG */

Log:
HTDR_CPSS: 17:25:34:392 110309 L1811 cpssdd Remote Command: op= 53; arg= 0x35 0x0b 0x130 1 U1400.1B1.019DF02-P1-C3
HTDR_CPSS: 17:25:34:392 110313 L901 cpssdd mapRemoteCommand start: arg = 0x35 0x0b 0x130 1 U1400.1B1.019DF02-P1-C3
HTDR_CPSS: 17:25:34:392 110313 L912 cpssdd mapRemoteCommand: RAS op=0; op_str = 0x0b <-- op is expected to be 11
HTDR_CPSS: 17:25:34:392 110313 L921 cpssdd mapRemoteCommand: op= 0; op_str = 0x130 <-- op is expected to be 304

Any idea?

bastl · 03-13-2011, 11:27 AM

Quote:

Originally Posted by yoavf

I am trying to convert hex string to integer using some lib utility, instead of writing it myself.
sscanf, strtol failed to pass compilation.

If think you've read c++ references like http://www.cplusplus.com/reference/c...cstdio/sscanf/

I can not figure out what you want to do, e.g what you mean with "hex string" - is it a data stream, a simple string of bytes with values from 32 to 255 terminated by 0, ... ?
And explain what you want to convert:
-data coming from X having this
-data structur
-have to be converted to structure Y because ...
-to can be used for what (to do)

theNbomr · 03-13-2011, 04:29 PM

Have you #included the correct C headers, such as <stdio.h>, <stdlib.h>, etc. ?

--- rod.

yoavf · 03-14-2011, 09:55 AM

Thanks Guys,
Guess I will have to write a small routine.
Thanks anyway

ira · 03-16-2011, 02:14 AM

Hello Yoavf,

I have the same requirement, but i cannot figure out how to do it.
Could you please share what you have done?

Thanx in advance.

ira · 03-16-2011, 02:17 AM

What i exactly wanted is to retrieve an integer I get inside a char buffer.
(I.e., convert a char* to a unsigned long value)

"simple_strtoul" function does what i exaclty wanted.

theNbomr · 03-16-2011, 08:35 AM

Quote:

Originally Posted by yoavf

I am a beginner with device drivers

I am trying to convert hex string to integer using some lib utility, instead of writing it myself.
sscanf, strtol failed to pass compilation.
Then I tried atoi, which returns 0.

Why did these fail to compile? The compiler doesn't know that it is compiling a device driver, so it should be just standard C.

Code:

/* sscanfTest.c  */
#include	<stdio.h>
#include	<stdlib.h>

int	main( int argc, char * argv[] ){

int	hexArg1, hexArg2, hexArg3, decArg1;
char	stringArg[1024];	/* Arbitarily large  */
	
	sscanf( argv[1], "%x %x %x %d %s", &hexArg1, &hexArg2, &hexArg3, &decArg1, stringArg );
	
	printf( "Integers: %d %d %d %d\n", hexArg1, hexArg2, hexArg3, decArg1 );
	printf( "String: %s\n", stringArg );
	
	exit(0);
}

Build and run...

Code:

make sscanftest
cc     sscanfTest.c   -o sscanfTest
./sscanfTest '0x35 0x0b 0x130 1 U1400.1B1.019DF02-P1-C3'
Integers: 53 11 304 1
String: U1400.1B1.019DF02-P1-C3

--- rod.

yoavf · 03-22-2011, 05:10 AM

Hello ira,
Sorry, but I was not permitted to send the routine.
You will have to think how to build the number by translating each digit from ascii to integer, then consider the position in the number.

Good luck