将NSString转换为c字符串时，字符串复制函数不返回值strcpy

Question

sipurl and regurl are NSString which I get from UItextField

    const char *sipAddr = [sipUrl cStringUsingEncoding:NSUTF8StringEncoding];
    const char *regAddr = [regUrl cStringUsingEncoding:NSUTF8StringEncoding];
    const char *uname = [orgUsername cStringUsingEncoding:NSUTF8StringEncoding];
    const char *pword = [password cStringUsingEncoding:NSUTF8StringEncoding];
    //const char *pword = [password UTF8String];
    const char *realm = [realmStr cStringUsingEncoding:NSUTF8StringEncoding];

    //char *sipAddrArr=strdup(sipAddr);
    //char *regAddrArr=strdup(regAddr);
    //char *unamearr=strdup(uname);
    //char *pwordarrnew = strdup(pword);

    char sipAddrArr[[sipUrl length]];
    strcpy(sipAddrArr,sipAddr);

    char regAddrArr[[regUrl length]];
    strcpy(regAddrArr,regAddr);

    char unamearr[[orgUsername length]] ;
    strcpy(unamearr, uname);

    char pwordarrnew[[password length]];
    strcpy(pwordarrnew,pword);

    char realmchr[[realmStr length]];
    strcpy(realmchr,realm);
    char pwordarr1[] = {"10000"};
    printf("\nPassword value sent: %s",pword);
    printf("\nPassword value sent: %s",pwordarr1);

pword has value while trying to copy constant char to char I use strcpy function it returns no value for pword. The same code works fine when testing in simulator but doesn't work when connected to iOS phone.

Answer 1

This may or may not be the cause of your problem, but it is an error in your code:

You are taking an NSString , converting it into a UTF8 C-string, and then copying the C-string into a C-array sized according to the length of the NSString . This is wrong, the NSString and its UTF8 translation can be different lengths. You need to determine the length of the UTF8 string and allow for the end-of-string marker. For example:

char sipAddrArr[strlen(sipAddr)+1];
strcpy(sipAddrArr,sipAddr);

and similarly for the other arrays.

HTH