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What linux shell command returns a part of a string? [duplicate]
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what do we need to do if we want to start from 3rd char till end of the string ie: "abcdef" we need cdef then echo "abcdef" | cut -c3?"
– user1731553
Apr 5 '16 at 5:46
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List of all special characters that need to be escaped in a regex
...a regex for matching the message. The template/message may contain special characters.
10 Answers
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Convert Elixir string to integer or float
...k String.to_integer/1 and String.to_float/1.
Hint: See also to_atom/1,to_char_list/1,to_existing_atom/1for other conversions.
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Creating a daemon in Linux
...nlog(3), closelog(3)
And here is a more general function,
int
daemonize(char* name, char* path, char* outfile, char* errfile, char* infile )
{
if(!path) { path="/"; }
if(!name) { name="medaemon"; }
if(!infile) { infile="/dev/null"; }
if(!outfile) { outfile="/dev/null"; }
if(!e...
Objective-C and Swift URL encoding
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To escape the characters you want is a little more work.
Example code
iOS7 and above:
NSString *unescaped = @"http://www";
NSString *escapedString = [unescaped stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHo...
Concatenate strings in Less
...e it was changing my background-image url, and I wasn't too sure how to do concatenation :)
– hatsrumandcode
Dec 22 '15 at 16:18
7
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C/C++ NaN constant (literal)?
...> offers the below functions:
#include <math.h>
double nan(const char *tagp);
float nanf(const char *tagp);
long double nanl(const char *tagp);
which are like their strtod("NAN(n-char-sequence)",0) counterparts and NAN for assignments.
// Sample C code
uint64_t u64;
double x;
x = nan("0...
Is there a difference between YES/NO,TRUE/FALSE and true/false in objective-c?
...them from their #define values.
Importantly, never test booleans using a character comparison -- it's not only risky because someVar could be assigned a non-zero value which is not YES, but, in my opinion more importantly, it fails to express the intent correctly:
if(someVar==YES) { ... } // don'...
How to detect READ_COMMITTED_SNAPSHOT is enabled?
...null_dflt_on SET
ansi_warnings SET
ansi_padding SET
ansi_nulls SET
concat_null_yields_null SET
isolation level read committed
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Maximum length of the textual representation of an IPv6 address?
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45 characters.
You might expect an address to be
0000:0000:0000:0000:0000:0000:0000:0000
8 * 4 + 7 = 39
8 groups of 4 digits with 7 : between them.
But if you have an IPv4-mapped IPv6 address, the last two groups can b...