re: Bash file to variable string problem -- must be simple. What am I missing?

[deb <deb@rangingthoughts.org>]

On 3/2/19 8:07 PM, Roberto C. Sánchez wrote:

On Sat, Mar 02, 2019 at 07:56:58PM -0500, deb wrote:

   This has to be simple and I'm just missing it.

   If I pull a filename from a temp file into a variable, I can ls it fine.

   If I cut off the extension, and tack on my own SAME EXT, ls no longer
   works.

   (The actual script is more elaborate, loading vlc , etc -- but this
   summarizes & shows my issue)

   # mp4file.txt holds just 'long file with spaces.mp4'

   fname=$(<mp4file.txt)

   # echo $fname shows the right filename.mp4 string

   # works
   ls -al "$fname"

   # Cut off the extension.
   fname=`echo $fname | rev | cut -d. -f2 | rev`

   # echo $fname shows the filename sans '.mp4'

   # THIS LS FAILS, WITH FILE NOT FOUND (but actually reports the exact
   string that worked above, but not being found here).

   ls -al "$fname".mp4

   ls: cannot access 'long file with spaces.mp4': No such file or directory

I cannot replicate the behavior you describe.  Here is how it looks for
me:

root@chroot:~# touch "long file with spaces.mp4"
root@chroot:~# echo "long file with spaces.mp4" >mp4file.txt
root@chroot:~# cat mp4file.txt 
long file with spaces.mp4
root@chroot:~# ls -l
total 4
-rw-r--r-- 1 root root  0 Mar  3 01:02 long file with spaces.mp4
-rw-r--r-- 1 root root 26 Mar  3 01:02 mp4file.txt
root@chroot:~# fname=$(<mp4file.txt)
root@chroot:~# ls -al "$fname"
-rw-r--r-- 1 root root 0 Mar  3 01:02 long file with spaces.mp4
root@chroot:~# fname=`echo $fname | rev | cut -d. -f2 | rev`
root@chroot:~# ls -al "$fname".mp4
-rw-r--r-- 1 root root 0 Mar  3 01:02 long file with spaces.mp4

What version of bash are you using?

   ------------------------------------------------------

   It is not:

   * a special character thing,

   * a carriage return thing,

   * a character case thing,

   * not helped with './' or '~/' added in front of the filename.

   * It's the same string in both spots.

   Any thoughts folks?

I am not sure about the overall problem, but I can say I would replace
this:

fname=`echo $fname | rev | cut -d. -f2 | rev`

with this:

fname=$(basename "$fname" .mp4)

Regards,

-Roberto

Thank you Roberto.

# Cut off the extension.
# fname=`echo $fname | rev | cut -d. -f2 | rev`

fname=$(basename "$fname" .mp4)

^ this does work for the ls, but I do not know that it will be a .mp4.

(It could be a .mkv, .webm, .ogg, .mp4, etc.)

What is certain is the filename to  the left of the final '.'.

So I was building up the different choices to file test for, hence the fname=`echo $fname | rev | cut -d. -f2 | rev`

I'm running:

cat /etc/issue
9.8

bash --version
GNU bash, version 4.4.12(1)-release (x86_64-pc-linux-gnu)