how to get file descriptor of process.{stdin,stdout,stderr} #2136

Activity

1. addaleax commented on Aug 21, 2019

   

   addaleax

   on Aug 21, 2019

   Member

   More actions

   Is process.stdin.fd, process.stdout.fd, process.stderr.fd what you’re looking for? They do have fixed values, i.e. 0, 1 and 2, unless you are running code inside a Worker (in which case they are not associated with fds) or the streams have been overwritten with other objects.

   👍React with 👍3Reacted by Alexander Mills, Jhony López and William Stein
2. ORESoftware commented on Aug 22, 2019

   

   ORESoftware

   on Aug 22, 2019

   Author

   More actions

   that should do, i think i had this same problem before, typescript typings didnt mention the fd's
3. gireeshpunathil commented on Dec 27, 2019

   

   gireeshpunathil

   on Dec 27, 2019

   Member

   More actions

   closing as answered
4. gireeshpunathil

   closed this as completedon Dec 27, 2019
5. HarshithaKP

   added a commit that references this issue on Jan 17, 2020

   doc: document process.std*.fd

   ...

   bab9baf
6. addaleax

   added a commit that references this issue on Jan 20, 2020

   doc: document process.std*.fd

   ...

   343ddff
7. codebytere

   added 2 commits that reference this issue on Mar 14, 2020

   doc: document process.std*.fd

   ...

   071bbea

   doc: document process.std*.fd

   ...

   5e8f8b8
8. ORESoftware commented on Mar 30, 2020

   

   ORESoftware

   on Mar 30, 2020

   Author

   More actions

   anyone know how this can be accomplished given a file descriptor perhaps in a Node.js process?
   https://unix.stackexchange.com/questions/576954/discover-what-file-stdout-is-being-written-to
9. martian17 commented on Apr 3, 2023

   

   martian17

   on Apr 3, 2023

   Last edited by martian17

   More actions

   process.stdin.fd seems to induce EAGAIN error when passed as an argument to fs.readSync.
   When passing a literal 0 no error is thrown.
   If this is a bug I'll file an issue.
   Here is an example code

   const fs = require("fs");
   
   const getchar = function(){
       const buffer = Buffer.alloc(1);
       fs.readSync(process.stdin.fd/*0*/, buffer, 0, 1);
       return buffer[0];
   };
   
   const readline = function(pmt){
       process.stdout.write(pmt);
       let c;
       const buff = [];
       while((c = getchar()) !== '\n'.charCodeAt(0)){
           buff.push(c);
       }
       return Buffer.from(buff).toString("utf8");
   }
   
   const age = readline("your age: ");
   console.log(`You are ${age} years old`);
   const name = readline("your name: ");
   console.log(`Your name is ${name}`);