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How to check if a String contains only ASCII?
The call Character.isLetter(c) returns true if the character is a letter. But is there a way to quickly find if a String only contains the base characters of ASCII?
...
How can I hash a password in Java?
...te[16];
random.nextBytes(salt);
KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 65536, 128);
SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] hash = f.generateSecret(spec).getEncoded();
Base64.Encoder enc = Base64.getEncoder();
System.out.printf("salt: %s...
Why is a boolean 1 byte and not 1 bit of size?
...
Historically, a byte was the number of
bits used to encode a single character
of text in a computer and it is
for this reason the basic addressable
element in many computer
architectures.
So byte is the basic addressable unit, below which computer architecture cannot address. And si...
What is the meaning of “__attribute__((packed, aligned(4))) ”
...es in some cases. Consider the following structure:
typedef struct
{
char Data1;
int Data2;
unsigned short Data3;
char Data4;
}sSampleStruct;
sizeof(sSampleStruct) will be 12 rather than 8. Because of structure padding. By default, In X86, structures will be padded to 4-byte ...
What does the unary plus operator do?
... answered Oct 11 '10 at 2:07
Charles SalviaCharles Salvia
47.1k1212 gold badges116116 silver badges137137 bronze badges
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Creating a new directory in C
...ng a gnu extension to print the error message with printf.
void rek_mkdir(char *path) {
char *sep = strrchr(path, '/');
if(sep != NULL) {
*sep = 0;
rek_mkdir(path);
*sep = '/';
}
if(mkdir(path, 0777) && errno != EEXIST)
printf("error while try...
In C/C++ what's the simplest way to reverse the order of bits in a byte?
...
This should work:
unsigned char reverse(unsigned char b) {
b = (b & 0xF0) >> 4 | (b & 0x0F) << 4;
b = (b & 0xCC) >> 2 | (b & 0x33) << 2;
b = (b & 0xAA) >> 1 | (b & 0x55) << 1;
retu...
Base64: What is the worst possible increase in space usage?
...y possibly become when converted to a Base64 string (assuming one byte per character)?
5 Answers
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Use C++ with Cocoa Instead of Objective-C?
...ving it an extension of .mm, or by right-clicking on the file in Xcode and selecting Get Info > General then changing the File Type to sourcecode.cpp.objcpp. The second option is useful if you have a .cpp file where you want to use Objective-C within a Mac-specific #ifdef.
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How do I grant myself admin access to a local SQL Server instance?
...he "SQL Server Configuration Manager", right click the server instance and select properties, go to the tab "Startup Parameters" and add -m.
– maets
May 5 '15 at 13:32
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