...should put the string "string" into the variable named abcdef.
This is how it's often used:
...but note that it takes a variable name -- a string -- not the variable itself. You can feed it whatever string you please, derived from whatever variables you please, and do things that would otherwise require ugly insecure eval hacks.
You can redirect into it any way you please. <<< is an ordinary redirection in BASH which replaces stdin with a string.
These 2 Users Gave Thanks to Corona688 For This Post:
Using bash, I'm trying to read a .properties file (name=value pairs), assigning an indirect variable reference for each line in the file.
The trick is that a property's value string may contain the name of a property that occurred earlier in the file, and I want the name of the 1st property to... (5 Replies)
The construct ${#parameter} returns the number of characters in the parameter and ${!parameter} specifies an indirect variable. My question is: How do I combine these two. What I want is ${#!parameter} but this gives an error.
Of course I can use:
dummy=${!parameter}
${#dummy}
but that's a... (0 Replies)
Ummm can anybody help me with this one?
Its prob quite simple.
I bascially have a file name say J1x2x3x7.dat
Im using the file name as a variable in a bash script. Want I want to do is extract most of the file name and make it a new variable expect with say one of the number now a... (2 Replies)
Hi,
I've got a small problem.
If varible A stores "B" and Variable B stores C,
How to get the value of variable B by using only Variable A..?
I tried the following but didnt work pease help..
$ var1=vikram
$ echo $var1
vikram
$ vikram=sampath
$ echo $vikram
sampath
$ echo... (6 Replies)
Hi
I have variable A_B=alpha
also var1="A"
var2="B"
I want to retrieve the value alpha using var1 and var2 , somthing like
echo ${${var1}_${var2}} that works. Obviously this is receiving syntax
error (6 Replies)
Hello,
is there a kind soul who can answer me, does the SH support double substitution known as indirect expansion similar to BASH? The syntax for bash is ${!var}.
For instance in bash I can write something like this:
VAR="value"
REF_VAR="VAR"
echo ${!REF_VAR}
and get the "value"... (1 Reply)
I have a file with two columns of numbers (member IDs):
1 1
2 1
3 1
4 2
5 4
6 1
7 5
8 3
9 2
Think of column 1 as the referee and column 2 as the referrer.
Is there a good way to backtrack who referred who? I would like an output, for this example here to be:
1 1
2 1
3 1
4 2 1 (2 Replies)
Sometimes it is handy to protect long scripts in C++.
The following syntax works fine for simple commands:
#define SHELLSCRIPT1 "\
#/bin/bash \n\
echo \"hello\" \n\
"
int main ()
{
cout <<system(SHELLSCRIPT1);
return 0;
}
Unfortunately for there are problems for:
1d arrays:... (10 Replies)
Trying to do so
echo "111:222:333" |awk -F: '{system("export TESTO=" $2)}'But it doesn't work (2 Replies)
Discussion started by: urello
2 Replies
LEARN ABOUT DEBIAN
numm.one-bit-instrument
one-bit-instrument(7) Numm Tutorials one-bit-instrument(7)NAME
one bit instrument - how to make a gnarly synth with numm-run
SYNOPSIS
numm-run FILE
DESCRIPTION
In this tutorial we will learn how to live-code a one-bit synthesizer controlled by mouse position. It is intended as a gentle introduc-
tion to development with numm-run.
To get started, create a text file with the following method stubs:
def audio_out(a):
pass
def video_out(a):
pass
Save the file as onebit.py, and then launch it with numm-run:
numm-run onebit.py
You should see a blank window appear. We will now make some sound and light by changing the value of a in the audio_out and video_out
functions:
def audio_out(a):
a[::100] = 2**15
def video_out(a):
a.flat[::100] = 255
Save the file, and you should see and hear the sketch update. This is using numpy's array-indexing to turn every hundredth audio sample
and pixel-color on. The audio sample rate is by default 44100Hz, so it produces a series of clicks that will be perceived as a 441Hz tone.
We can turn this into an instrument by connecting mouse motion to frequency:
period = 100
def audio_out(a):
a[::period] = 2**15
def video_out(a):
a.flat[::period] = 255
def mouse_in(type,px,py,button):
global period
period = px*1000
Finally, let's use the keyboard to record and jump to notes. The first time you press a key, it records the period, and subsequant depres-
sions play the saved period:
period = 100
record = {}
def audio_out(a):
a[::period] = 2**15
def video_out(a):
a.flat[::period] = 255
def mouse_in(type,px,py,button):
global period
period = px*1000
def keyboard_in(type,key):
global period
if record.has_key(key):
period = record[key]
elif record.has_key(key):
record[] = period
SEE ALSO numm-run(1), numm.getting-started(7), numm.spectral-analysis(7)numm February 2012 one-bit-instrument(7)