Thread: convert unsigned char to char *

  1. #1
    Registered User
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    Feb 2006
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    convert unsigned char to char *

    OK I have a

    Code:
    char *arg which points to a char msg[1024]
    and I have a

    Code:
    unsigned char test[1024];
    now I want to convert the char into a unsigned char

    Code:
    snprintf(test,sizeof(test),"%s",arg);
    But I get the error message error C2664: '_snprintf' : cannot convert parameter 1 from 'unsigned char [1024]' to 'char *'

    What can I do?

  2. #2
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    all you have to do is typecast is. No other conversion necessary
    Code:
    snprintf((char*)test,sizeof(test),"%s",arg);
    snprintf() is overkill when all you want to do is copy one string to another
    Code:
    strncpy((char*)test,arg,sizeof(test));
    or use std::string class and you don't have to worry about buffer overflow
    Last edited by Ancient Dragon; 03-03-2006 at 06:38 PM.

  3. #3
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    71
    Quote Originally Posted by Ancient Dragon
    all you have to do is typecast is. No other conversion necessary
    Code:
    snprintf((char*)test,sizeof(test),"%s",arg);
    snprintf() is overkill when all you want to do is copy one string to another
    Code:
    strncpy((char*)test,arg,sizeof(test));
    or use std::string class and you don't have to worry about buffer overflow
    THX

    Could it be that in c or in old versions of c++ you don't have to care about convert a unsigned char to char *?

    My problem is that I have a blowfish .c file and a function int encrypt_string(char *key, char *str, char *dest, int len)
    but I have to give this function unsigned chars, because otherwise ascii codes above 127 get encrypt false. But my compiler strikes to give unsigned chars to this function.
    Last edited by keeper; 03-03-2006 at 06:58 PM.

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