使用node.js将文件描述符传递给子进程

这是结果: $ ./m.sh看看何时可以看到我们创建的文件描述符从主要的bash程序:总计0lrwx ------ 1 me me 64 Apr 16 12:16 0->/dev/pts/2l-wx ------ 1 me me 64 Apr 16 12:16 1->管道:[256648]lrwx ------ 1 me me 64 Apr 16 12:16 2->/dev/pts/2lr-x ------ 1 me me 64 Apr 16 12:16 255->/home/me/bashcov/m.shlrwx ------ 1 me me 64 Apr 16 12:16 3->/home/me/bashcov/messages从bash子程序直接调用:总计0lrwx ------ 1 me me 64 Apr 16 12:16 0->/dev/pts/2l-wx ------ 1 me me 64 Apr 16 12:16 1->管道:[256648]lrwx ------ 1 me me 64 Apr 16 12:16 2->/dev/pts/2lr-x ------ 1 me me 64 Apr 16 12:16 255->/home/me/bashcov/s.shlrwx ------ 1 me me 64 Apr 16 12:16 3->/home/me/bashcov/messages从javascript程序:总计0lrwx ------ 1 me me 64 Apr 16 12:16 0->/dev/pts/2l-wx ------ 1 me me 64 Apr 16 12:16 1->管道:[256648]lrwx ------ 1 me me 64 Apr 16 12:16 10->anon_inode:[事件投票]lr-x ------ 1 me me 64 Apr 16 12:16 11->管道:[256661]l-wx ------ 1 me me 64 Apr 16 12:16 12->管道:[256661]lrwx ------ 1 me me 64 Apr 16 12:16 13->anon_inode:[eventfd]lrwx ------ 1 me me 64 Apr 16 12:16 14->anon_inode:[事件投票]lr-x ------ 1 me me 64 Apr 16 12:16 15->管道:[258179]l-wx ------ 1 me me 64 Apr 16 12:16 16->管道:[258179]lrwx ------ 1 me me 64 Apr 16 12:16 17->anon_inode:[eventfd]lr-x ------ 1 me me 64 Apr 16 12:16 18->/dev/空lrwx ------ 1 me me 64 Apr 16 12:16 19->anon_inode:[事件投票]lrwx ------ 1 me me 64 Apr 16 12:16 2->/dev/pts/2lr-x ------ 1 me me 64 Apr 16 12:16 20->管道:[258182]l-wx ------ 1 me me 64 Apr 16 12:16 21->管道:[258182]lrwx ------ 1 me me 64 Apr 16 12:16 22->anon_inode:[eventfd]lrwx ------ 1 me me 64 Apr 16 12:16 3->/home/me/bashcov/messageslrwx ------ 1 me me 64 Apr 16 12:16 4->anon_inode:[事件投票]lr-x ------ 1 me me 64 Apr 16 12:16 5->管道:[258177]l-wx ------ 1 me me 64 Apr 16 12:16 6->管道:[258177]lr-x ------ 1 me me 64 Apr 16 12:16 7->管道:[258178]l-wx ------ 1 me me 64 Apr 16 12:16 8->管道:[258178]lrwx ------ 1 me me 64 Apr 16 12:16 9->anon_inode:[eventfd]从js调用的bash子程序中:总计0lrwx ------ 1 me me 64 Apr 16 12:16 0->/dev/pts/2l-wx ------ 1 me me 64 Apr 16 12:16 1->管道:[256648]lrwx ------ 1 me me 64 Apr 16 12:16 2->/dev/pts/2lr-x ------ 1 me me 64 Apr 16 12:16 255->/home/me/bashcov/s.sh 您可以看到，从node.js调用 s.sh 时，它无权访问我创建的文件描述符 3 .bash将其传递给它所调用的bash程序以及它所调用的节点程序，但是节点没有.我刚刚在python中遇到了这个问题( bashcov-如果python调用了子程序，则不起作用)，而解决方案竟然是添加参数 close_fds = False .( os.system()与os.popen()相比，使用bash进程替代时:ls:无法访问'/dev/fd/63':没有此类文件或目录)如果我将本实验中的js程序替换为ruby或make程序，则效果很好.有没有办法告诉node.js的 child_process 在child_process上传递所有打开的文件描述符?解决方案将 stdio:'inherit'替换为 stdio:[0，1，2，3] .'inherit'是每个[0，1，2] 的简写.rel ="nofollow noreferrer">文档，因此，如果您也希望传递FD 3，则需要手动添加它.除了手动创建包含所有数字的数组之外，我没有其他方法可以告诉它继承每个FD.In order to use bashcov in one of my projects, I need a way to pass on all file descriptors from node.js to a child process.I have created these test programs:$ head -n20 m.sh r.js s.sh==> m.sh <==#! /usr/bin/env bashset -eexec 3<>messagesecho see when we can see the file descriptor we createdecho from main bash program:ls -l /proc/$$/fd/echoecho from bash subprogram called directly:./s.shechonode r.js ./s.shexec 3>&-==> r.js <==const run = function(cmd) { return require('child_process').spawnSync(cmd[0], cmd.slice(1), { stdio: 'inherit', });}console.log('from javascript program:');run(['ls', '-l', `/proc/${process.pid}/fd/`]);console.log('\nfrom bash subprogram called from js:');run(process.argv.slice(2))==> s.sh <==#! /usr/bin/env bashset -els -l /proc/$$/fd/The main program m.sh list all of its file descriptors, and then call a bash program that I have referred to as "subprogram" s.sh which also lists all of its fds. Then I call a js program r.js which lists its available fds, and then calls s.sh again using the child_process lib.This is the result:$ ./m.shsee when we can see the file descriptor we createdfrom main bash program:total 0lrwx------ 1 me me 64 Apr 16 12:16 0 -> /dev/pts/2l-wx------ 1 me me 64 Apr 16 12:16 1 -> pipe:[256648]lrwx------ 1 me me 64 Apr 16 12:16 2 -> /dev/pts/2lr-x------ 1 me me 64 Apr 16 12:16 255 -> /home/me/bashcov/m.shlrwx------ 1 me me 64 Apr 16 12:16 3 -> /home/me/bashcov/messagesfrom bash subprogram called directly:total 0lrwx------ 1 me me 64 Apr 16 12:16 0 -> /dev/pts/2l-wx------ 1 me me 64 Apr 16 12:16 1 -> pipe:[256648]lrwx------ 1 me me 64 Apr 16 12:16 2 -> /dev/pts/2lr-x------ 1 me me 64 Apr 16 12:16 255 -> /home/me/bashcov/s.shlrwx------ 1 me me 64 Apr 16 12:16 3 -> /home/me/bashcov/messagesfrom javascript program:total 0lrwx------ 1 me me 64 Apr 16 12:16 0 -> /dev/pts/2l-wx------ 1 me me 64 Apr 16 12:16 1 -> pipe:[256648]lrwx------ 1 me me 64 Apr 16 12:16 10 -> anon_inode:[eventpoll]lr-x------ 1 me me 64 Apr 16 12:16 11 -> pipe:[256661]l-wx------ 1 me me 64 Apr 16 12:16 12 -> pipe:[256661]lrwx------ 1 me me 64 Apr 16 12:16 13 -> anon_inode:[eventfd]lrwx------ 1 me me 64 Apr 16 12:16 14 -> anon_inode:[eventpoll]lr-x------ 1 me me 64 Apr 16 12:16 15 -> pipe:[258179]l-wx------ 1 me me 64 Apr 16 12:16 16 -> pipe:[258179]lrwx------ 1 me me 64 Apr 16 12:16 17 -> anon_inode:[eventfd]lr-x------ 1 me me 64 Apr 16 12:16 18 -> /dev/nulllrwx------ 1 me me 64 Apr 16 12:16 19 -> anon_inode:[eventpoll]lrwx------ 1 me me 64 Apr 16 12:16 2 -> /dev/pts/2lr-x------ 1 me me 64 Apr 16 12:16 20 -> pipe:[258182]l-wx------ 1 me me 64 Apr 16 12:16 21 -> pipe:[258182]lrwx------ 1 me me 64 Apr 16 12:16 22 -> anon_inode:[eventfd]lrwx------ 1 me me 64 Apr 16 12:16 3 -> /home/me/bashcov/messageslrwx------ 1 me me 64 Apr 16 12:16 4 -> anon_inode:[eventpoll]lr-x------ 1 me me 64 Apr 16 12:16 5 -> pipe:[258177]l-wx------ 1 me me 64 Apr 16 12:16 6 -> pipe:[258177]lr-x------ 1 me me 64 Apr 16 12:16 7 -> pipe:[258178]l-wx------ 1 me me 64 Apr 16 12:16 8 -> pipe:[258178]lrwx------ 1 me me 64 Apr 16 12:16 9 -> anon_inode:[eventfd]from bash subprogram called from js:total 0lrwx------ 1 me me 64 Apr 16 12:16 0 -> /dev/pts/2l-wx------ 1 me me 64 Apr 16 12:16 1 -> pipe:[256648]lrwx------ 1 me me 64 Apr 16 12:16 2 -> /dev/pts/2lr-x------ 1 me me 64 Apr 16 12:16 255 -> /home/me/bashcov/s.shYou can see that inside the s.sh when it is called from node.js, it does not have access to file descriptor 3 which I have created. bash passes it on to the bash program it calls, and the node program it calls, but node does not.I have just run into this issue with python (bashcov - does not work if subprogram is called by python) and the solution turned out to be to add the param close_fds=False. (os.system() vs. os.popen() when using bash process substitution: ls: cannot access '/dev/fd/63': No such file or directory)If I replace the js program in this experiment with a ruby or make program, it works fine.Is there a way to tell node.js's child_process to pass all the open file descriptors on the the child_process? 解决方案 Replace stdio: 'inherit' with stdio: [0, 1, 2, 3]. 'inherit' is shorthand for [0, 1, 2], per the documentation, so if you want FD 3 to be passed too, you need to add it manually. I don't see a way to tell it to inherit every FD other than manually creating an array with all of their numbers. 这篇关于使用node.js将文件描述符传递给子进程的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 1403页，肝出来的..