node-red/nodes/core/core/75-exec.html

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<script type="text/x-red" data-template-name="exec">
    <div class="form-row">
        <label for="node-input-command"><i class="fa fa-file"></i> Command</label>
        <input type="text" id="node-input-command" placeholder="command">
    </div>
    <div class="form-row">
        <label for="node-input-append"><i class="fa fa-list"></i> Append</label>
        <input type="text" id="node-input-append" placeholder="extra input">
    </div>
    <div class="form-row">
        <label>&nbsp;</label>
        <input type="checkbox" id="node-input-useSpawn" placeholder="spawn" style="display: inline-block; width: auto; vertical-align: top;">
        <label for="node-input-useSpawn" style="width: 70%;">Use spawn() instead of exec() ?</label>
    </div>
    <div class="form-row">
        <label for="node-input-name"><i class="fa fa-tag"></i> Name</label>
        <input type="text" id="node-input-name" placeholder="Name">
    </div>
    <div class="form-tips">Tip: <i>spawn</i> expects only one command word - and appended args to be comma separated.</div>
</script>

<script type="text/x-red" data-help-name="exec">
    <p>Calls out to a system command.<br/></p>
    <p>Provides 3 outputs... stdout, stderr, and return code.</p>
    <p>By default uses exec() which calls the command, blocks while waiting for completion, and then returns the complete result in one go, along with any errors.</p>
    <p>Optionally can use spawn() instead, which returns output from stdout and stderr as the command runs (ie one line at a time). On completion it then returns a return code (on the 3rd output).</p>
    <p>Spawn only expect one command word, with all extra parameters to be comma separated and passed as the append.</p>
    <p>The optional append gets added to the command after the <b>msg.payload</b> - so you can do things like pipe the result to another command.</p>
    <p>If stdout is binary a <i>buffer</i> is returned - otherwise returns a <i>string</i>.</p>
</script>

<script type="text/javascript">
    RED.nodes.registerType('exec',{
        category: 'advanced-function',
        color:"darksalmon",
        defaults: {
            command: {value:"",required:true},
            append: {value:""},
            useSpawn: {value:""},
            name: {value:""}
        },
        inputs:1,
        outputs:3,
        icon: "arrow-in.png",
        align: "right",
        label: function() {
            return this.name||this.command;
        },
        labelStyle: function() {
            return this.name?"node_label_italic":"";
        }
    });
</script>