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Accept input via stdin and arguments in a command line application in node.js
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| #!/usr/bin/env node | |
| var args = process.argv.slice(2); | |
| var input = args[0]; | |
| var isTTY = process.stdin.isTTY; | |
| var stdin = process.stdin; | |
| var stdout = process.stdout; | |
| // If no STDIN and no arguments, display usage message | |
| if (isTTY && args.length === 0) { | |
| console.log("Usage: "); | |
| } | |
| // If no STDIN but arguments given | |
| else if (isTTY && args.length !== 0) { | |
| handleShellArguments(); | |
| } | |
| // read from STDIN | |
| else { | |
| handlePipedContent(); | |
| } | |
| function handlePipedContent() { | |
| var data = ''; | |
| stdin.on('readable', function() { | |
| var chuck = stdin.read(); | |
| if(chuck !== null){ | |
| data += chuck; | |
| } | |
| }); | |
| stdin.on('end', function() { | |
| stdout.write(uppercase(data)); | |
| }); | |
| } | |
| function handleShellArguments(){ | |
| console.log(uppercase(input)); | |
| } | |
| function uppercase(data){ | |
| return data.toUpperCase(); | |
| } |
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| $ echo bob | node read_arguments.js | |
| BOB | |
| $ node read_arguments.js bob | |
| BOB | |
| $ node read_arguments.js | |
| Usage: filename <input> |
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