mjhjmtu

I teach an Intro to UNIX/Linux course at a local college and one of my students asked the following question:

Why are some of the files in my directory colored white and others are gray? Are the white ones the ones I created today and the gray are existing files?

As I looked into this I first thought the answer would be in the LS_COLORS variable, but further investigation revealed that the color listings were different when using the -l switch versus the -al switch with the ls command. See the following screen shots:

Using ls -l the file named '3' shows as white but using the -al switch the same file shows a gray.

Is this a bug in ls or does anyone know why this is happening?

It looks as if your prompt-string ($PS1) is setting the bold attribute on characters to make the colors nicer, and not unsetting it. The output from ls doesn't know about this, and does unset bold. So after the first color output of ls, everything looks dimmer.

The whole output of ls will be printed in the last active color. If ls is called without color:

$ printf 'e[0;31m color testn'; /bin/ls
 color test
filea fileb filec filed filee filef fileg fileh

will print the list of files in red.

Or, if there is no color change needed for ls, the last color will remain:

$ mkdir t1; cd t1; touch filea..h
$ printf 'e[0;31m color testn'; /bin/ls --color -l
 color test
total 0
-rw-r--r-- 1 user user 0 Feb 23 01:16 filea
-rw-r--r-- 1 user user 0 Feb 23 01:16 fileb
-rw-r--r-- 1 user user 0 Feb 23 01:16 filec
-rw-r--r-- 1 user user 0 Feb 23 01:16 filed
-rw-r--r-- 1 user user 0 Feb 23 01:16 filee
-rw-r--r-- 1 user user 0 Feb 23 01:16 filef
-rw-r--r-- 1 user user 0 Feb 23 01:16 fileg
-rw-r--r-- 1 user user 0 Feb 23 01:16 fileh

Still, all in red.

But, as soon as ls needs to set a color (and then reset colors to the default used by the console), the color used from then on will be the console default.

$ printf 'e[0;31m color testn'; /bin/ls --color -la
 color test
total 8
drwxr-xr-x 2 user user 4096 Feb 23 01:16 .
drwxr-x--- 7 user user 4096 Feb 23 01:15 ..
-rw-r--r-- 1 user user 0 Feb 23 01:16 filea
-rw-r--r-- 1 user user 0 Feb 23 01:16 fileb
-rw-r--r-- 1 user user 0 Feb 23 01:16 filec
-rw-r--r-- 1 user user 0 Feb 23 01:16 filed
-rw-r--r-- 1 user user 0 Feb 23 01:16 filee
-rw-r--r-- 1 user user 0 Feb 23 01:16 filef
-rw-r--r-- 1 user user 0 Feb 23 01:16 fileg
-rw-r--r-- 1 user user 0 Feb 23 01:16 fileh

With the first three lines (up to the blue dot) printed in red.