CODEWITHSUNDEEP
c++config
LKB
LKB

Reputation: 1040

GetPrivateProfileStringA() cutting off my config value number

I am calling the method GetPrivateProfileStringA() in order to read values from a config.ini file, but when one of my values is over 3 digits, it cuts the value down to 3 (1234 would become 123).

I have a config.ini file which looks like this:

[PASSPORT]
MinWidth=200
MinHeight=300

[FEATURES]
MinEyeDistance=20
MaxEyeDistance=1000
...

I am reading this config.ini file using the following code:

char iniFilename[] = "C:\\config.ini";
char *iniVal = new char[256];

//check config.ini exists
if (std::ifstream(iniFilename))
{
    GetPrivateProfileStringA("PASSPORT", "MinWidth", "200", iniVal, sizeof(iniVal), iniFilename);
    configParam->minImageWidth = atol(iniVal);
    GetPrivateProfileStringA("PASSPORT", "MinHeight", "300", iniVal, sizeof(iniVal), iniFilename);
    configParam->minImageHeight = atol(iniVal);

    GetPrivateProfileStringA("FEATURES", "MinEyeDistance", "10", iniVal, sizeof(iniVal), iniFilename);
    configParam->minEyeDist = atol(iniVal);
    GetPrivateProfileStringA("FEATURES", "MaxEyeDistance", "1000", iniVal, sizeof(iniVal), iniFilename);
    configParam->maxEyeDist = atol(iniVal);
}

The buffer string itself (iniVal) gets 3 digits only, so I don't believe it has anything to do with converting the value to a long.

This is my configParam struct:

typedef struct _CONFIG_PARAMS
{
    long minImageWidth;
    long minImageHeight;
    long minEyeDist;
    long maxEyeDist;
} STRUCT_CONFIG_PARAMS;

I'm kind of lost as to why this is happening. Any help is appreciated!

Upvotes: 0

Views: 2504

Answers (1)

Nick Nougat
Nick Nougat

Reputation: 191

You are using sizeof() for iniVal, which will return the size of pointer to char, not the size of the dynamically allocated array. Since this is 4 on your platform it leads to a truncation to 3 chars and a '\0'.

Either allocate iniVal on the stack using

char iniVal[256];

or use a constant to allocate the array and then pass this to GetPrivateProfileStringA() as in

const size_t ArraySize = 256;
char *iniVal = new char[ArraySize];
...
GetPrivateProfileStringA("PASSPORT", "MinWidth", "200", iniVal, ArraySize , iniFilename);

Upvotes: 2

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