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How can I add a help method to a shell script?
...
here's an example for bash:
usage="$(basename "$0") [-h] [-s n] -- program to calculate the answer to life, the universe and everything
where:
-h show this help text
-s set the seed value (default: 42)"
seed=42
while getopts ':hs:' option; do
case "$option" i...
What's the best way to check if a String represents an integer in Java?
...ncerned with potential overflow problems this function will perform about 20-30 times faster than using Integer.parseInt().
public static boolean isInteger(String str) {
if (str == null) {
return false;
}
int length = str.length();
if (length == 0) {
return false;
...
Comparing strings with == which are declared final in Java
...le (non-final version) is compiled to the following byte code:
Code:
0: ldc #2; //String str
2: astore_1
3: ldc #3; //String ing
5: astore_2
6: new #4; //class java/lang/StringBuilder
9: dup
10: invokespecial #5; //Method java/lang/StringBuilder."&l...
How to assign string to bytes array
...ices in Go is using a slice of bytes []byte and not a set array of bytes [20]byte when converting a string to bytes... Don't believe me? Check out Rob Pike's answer on this thread
– openwonk
Feb 14 '16 at 0:44
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How to show line number when executing bash script
...rrently executing).
For example, if your script reads:
$ cat script
foo=10
echo ${foo}
echo $((2 + 2))
Executing it thus would print line numbers:
$ PS4='Line ${LINENO}: ' bash -x script
Line 1: foo=10
Line 2: echo 10
10
Line 3: echo 4
4
http://wiki.bash-hackers.org/scripting/debuggingtips gi...
How to generate keyboard events in Python?
...
+50
It can be done using ctypes:
import ctypes
from ctypes import wintypes
import time
user32 = ctypes.WinDLL('user32', use_last_error=T...
What does multicore assembly language look like?
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10 Answers
10
Active
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Boolean operators && and ||
...
350
The shorter ones are vectorized, meaning they can return a vector, like this:
((-2:2) >= 0) ...
How can I round down a number in Javascript?
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edited Sep 30 '19 at 10:01
Gerrit Bertier
3,1071515 silver badges2727 bronze badges
answer...
Checking for the correct number of arguments
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#!/bin/sh
if [ "$#" -ne 1 ] || ! [ -d "$1" ]; then
echo "Usage: $0 DIRECTORY" >&2
exit 1
fi
Translation: If number of arguments is not (numerically) equal to 1 or the first argument is not a directory, output usage to stderr and exit with a failure status code.
More friendly er...