Linux bash Shell脚本-文件名中的空格

Question

It has been a long time since I did much bash script writing.

This is a bash script to copy and rename files by deleting all before the first period delimiter:

#!/bin/bash

mkdir fullname
mv *.audio fullname
cd fullname

for x in * ;
do
  cp $x ../`echo $x | cut -d "." -f 2-`
done

cd ..
ls

It works well for file names with no embedded spaces but not for those with spaces.

How can I change the code to fix this simple Linux bash script? Any suggestions for improving the code for other reasons would also be welcome.

Example filenames, some with embedded spaces and some not (from link)

http://www.homenetvideo.com/demo/index.php?/Radio%20%28VLC%29

Ambient.A6.SOMA Space Station.audio
Blues.B9.Blues Radio U.K.audio
Classical.K3.Radio Stephansdom - Vienna.audio
College.CI.KDVS U of California, Davis.audio
Country.Q1.K-FROG.audio
Easy.G4.WNYU.audio
Eclectic.M2.XPN.audio
Electronica.E2.Rinse.audio
Folk.F1.Radionomy.audio
Hiphop.H1.NPR.audio
Indie.I4.WAUG.audio
Jazz.J6.KCSM.audio
Latin.L3.Mega.audio
Misc.X7.Gaydio.audio
News.N9.KQED.audio
Oldies.O1.Lonestar.audio
OldTime.Y1.Roswell.audio
Progressive.P1.Aural Moon.audio
Rock.R8.WXRT.audio
Scanner.Z3.Montreal.audio
Soul.S1.181.FM.audio
Talk.T2.TWiT.audio
World.W3.Persian.audio

http://lh5.googleusercontent.com/-QjLEiAtT4cw/U98_UFcWvvI/AAAAAAAABv8/gyPhbg8s7Bw/w681-h373-no/homenet-radio.png

Answer 1

Whenever you deal with file names that might have spaces in them, you must reference them as "$x" rather than just $x . That's what's causing your cp command to fail.

Your echo command is also problematic. Although echo does the right thing for simple spaces - it echoes a file named ABC as ABC - it will still fail if you have more than one consecutive space in the name, or whitespace that isn't a simple space character.

Instead of passing the file names to external programs for processing, which always requires getting them through the whitespace-hostile command line, you should use bash built-in functions for string manipulations wherever possible, eg ${x%%foo} , ${x#bar} and similar functions. The man page describes them under "Parameter expansion".

Answer 2

Here's my suggestion:

#!/bin/bash
shopt -s nullglob
mkdir fullname
mv *.audio fullname
(
  cd fullname || exit
  for x in *; do
    cp "$x" "../${x#*.}"
  done
)
ls

• nullglob prevents * from presenting itself if no file matches it. Just optional.
• () summons a subshell and saves you from changing back to another directory.
• || exit || exit terminates the subshell if cd fails to change directory.
• ${x#*.} removes the <first>. from $x and expands it.