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Why 0 is true but false is 1 in the shell?
...it code of 0 (the result of /bin/true). Otherwise they evaluate as false.
Strings are evaluated differently than exit codes:
if [ 0 ] ; then echo not null ; fi
if [ $(echo 0) ] ; then echo not null ; fi
if [ -z "" ] ; then echo null ; fi
The (( )) arithmetic operator interprets 1 and 0 as true ...
Count the number of occurrences of a character in a string in Javascript
I need to count the number of occurrences of a character in a string.
33 Answers
33
...
Is there any JSON Web Token (JWT) example in C#?
...turn sha.ComputeHash(value); } } }
};
}
public static string Encode(object payload, string key, JwtHashAlgorithm algorithm)
{
return Encode(payload, Encoding.UTF8.GetBytes(key), algorithm);
}
public static string Encode(object payload, byte[] keyBytes, JwtHa...
Stack smashing detected
...s protection variables (called canaries) which have known values. An input string of size greater than 10 causes corruption of this variable resulting in SIGABRT to terminate the program.
To get some insight, you can try disabling this protection of gcc using option -fno-stack-protector while co...
Strings as Primary Keys in SQL Database [closed]
... slower from a performance standpoint (inserting/updating/querying) to use Strings for Primary Keys than integers?
15 Ans...
Output first 100 characters in a string
Can seem to find a substring function in python.
8 Answers
8
...
Check if a class has a member function of a given signature
...value = type::value;
};
Usage:
struct X {
int serialize(const std::string&) { return 42; }
};
struct Y : X {};
std::cout << has_serialize<Y, int(const std::string&)>::value; // will print 1
sh...
Multi-line string with extra space (preserved indentation)
...t; EndOfMessage
This is line 1.
This is line 2.
Line 3.
EndOfMessage
The string after << indicates where to stop.
To send these lines to a file, use:
cat > $FILE <<- EOM
Line 1.
Line 2.
EOM
You could also store these lines to a variable:
read -r -d '' VAR << EOM
This is l...
How to convert std::string to lower case?
I want to convert a std::string to lowercase. I am aware of the function tolower() , however in the past I have had issues with this function and it is hardly ideal anyway as use with a std::string would require iterating over each character.
...
How to know what the 'errno' means?
...
You can use strerror() to get a human-readable string for the error number. This is the same string printed by perror() but it's useful if you're formatting the error message for something other than standard error output.
For example:
#include <errno.h>
#include ...