child_process spawn()中的通配符? [英] Wildcards in child_process spawn()?

问题描述

我想在node.js中执行带有"doSomething ./myfiles/*.csv"的命令.我想使用spawn而不是exec，因为这是某种监视过程，因此我需要stdout输出.

I want to execute a command like "doSomething ./myfiles/*.csv" with spawn in node.js. I want to use spawn instead of exec, because it is some kind of watch process and I need the stdout output.

我尝试过

var spawn = require('child_process').spawn; 
spawn("doSomething", ["./myfiles/*.csv"]);

但是通配符* .csv不会被解释.

But then the wildcard *.csv will not interpreted.

使用spawn()时是否不能使用通配符?还有其他解决此问题的可能性吗?

Is it not possible to use wildcards when using spawn()? Are there other possibilities to solve this problem?

谢谢

托本

推荐答案

*正在由外壳扩展，对于child_process.spawn，参数将作为字符串传递，因此将永远无法正确扩展.这是spawn的限制.您可以尝试使用child_process.exec代替，它将允许Shell适当地扩展任何通配符:

The * is being expanded by the shell, and for child_process.spawn the arguments are coming through as strings so will never get properly expanded. It's a limitation of spawn. You could try child_process.exec instead, it will allow the shell to expand any wildcards properly:

var exec = require("child_process").exec;

var child = exec("doSomething ./myfiles/*.csv",function (err,stdout,stderr) {
    // Handle result
});

如果由于某些原因确实需要使用spawn，也许您可​​以考虑使用诸如 node-glob ?

If you really need to use spawn for some reason perhaps you could consider expanding the wildcard file pattern yourself in Node with a lib like node-glob before creating the child process?

在Joyent Node核心代码中，我们可以观察到一种通过spawn在shell中调用任意命令，同时保留完整的shell通配符扩展的方法:

In the Joyent Node core code we can observe an approach for invoking an arbitrary command in a shell via spawn while retaining full shell wildcard expansion:

https://github.com/joyent/node/blob/937e2e351b2450cf1e9c4d8b3lib /child_process.js#L589

这是一些伪代码:

var child;
var cmd = "doSomething ./myfiles/*.csv";

if ('win32' === process.platform) {
    child = spawn('cmd.exe', ['/s', '/c', '"' + cmd + '"'],{windowsVerbatimArguments:true} );
} else {
    child = spawn('/bin/sh', ['-c', cmd]);
}

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