Introduction

csound-nstrexists provides a simple way to check whether an instrument number exists in the orchestra, at i-rate or k-rate. An example csd is provided in the examples/ directory demonstrating i and k-rate operation. This depends on changes in a commit from 2019-09-12 so it will not work with builds older than that. The first stable Csound release with the relevant changes is 6.14.0

The opcode has only been tested on Linux as of writing.

Requirements

• Csound development libraries 6.14.0 or later
• Cmake 2.8.12 or later

Building

Create a build directory at the top of the source tree, execute cmake .., make and optionally make install as root. If the latter is not used/possible then the resulting libnstrexists module can be used with the --opcode-lib flag in Csound. eg:

cd csound-nstrexists
mkdir build && cd build
cmake ..
make && sudo make install

Opcode overview

nstrexists

iexists nstrexists instrnum

kexists nstrexists knstrnum

Check if an instrument exists given the instrument number.

• iexists | kexists : 1 if instrument is found, 0 if not
• instrnum | knstrnum : the instrument number to check