Update linux_basics.md

docs/linux_basics.md

@@ -518,19 +518,20 @@ $ ls -l
 
 - `<mode>` can be e.g.:
   -  `u+x` : lets You (owner) run a script you just wrote
-  -  `-w` : no write permissions for **owner+group** (warning: if `w` was set for others it will be kept!!)
+  -  `-w` : no write permissions for **owner+group**
+    - warning: if `w` was already set for *others* it will be kept!!
   -  `+rw` : let user and group members read and edit this file, not others if not already set
   -  `=xw` : let group members go into your directory and put files there, but not see which files are there, others are not affected
   -  `a=xw` : set xw for everyone
 
 - chmod takes flags as usual, e.g.
   -  `-R` for recursive (i.e. all files and sub-directories therein)
 
-``````{solution} chmod 755 style - "octal bit mask”
+``````{solution} chmod 755 style - binary sum - "octal bit mask”
 
 - Online, you will come across e.g. `chmod 755`. What does this mean? It’s an "octal bit mask”:
 
-- Each digit correspond to the binary sum for the owner, group and others, respectively.
+- Each digit corresponds to the **binary sum** for the *owner*, *group* and *others*, respectively.
  
   - ``7 = 4 + 2 + 1 = r + w + x``   All permissions
   - ``5 = 4 + 0 + 1 = r +   + x``   Read and execute permission