Unix File Permissions - Does Write Imply Read?

Question

If a file had write permissions only, how could a user exercise his right to edit the file if he could not read it? Does 'write' imply 'read' in Unix?

Accepted Answer

You may be blind and still be able to write:

```
 $ touch a
 $ chmod 0200 a
 $ ls -ln  a
 --w------- 1 1000 1000 4 Jul 19 15:13 a
 $ cat a
 $ cat: a: Permission denied
 $ echo "secret message" >> a
 $ chmod 0400 a
 $ cat a
 secret message
```

Nope :)

Unix File Permissions - Does Write Imply Read?

Solution

Problem