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I am trying to take a filename from the ~/Pictures folder and supply it as an argument for the nomacs command. The filename contains some spaces, so I am using Bash substitution to escape spaces (I also want to take last file in the folder).

The code: 

names=$(\ls ~/Pictures * | tac) 
SAVEIFS=$IFS
IFS=$'\n'
names=($names)
IFS=$SAVEIFS
screenshot=~/Pictures/${names[0]}
screenshot=${screenshot// /\\ }
nomacs $screenshot

Example of the filename: Screenshot from 2017-09-13 18-05-42.png

The problem is that nomacs $screenshot does not work but when I execute nomacs Screenshot\ from\ 2017-09-13 18-05-42.png, it works as expected.

Should I use some special Bash technique for escaping spaces?

syntagma
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    It is generally a [really bad idea](http://mywiki.wooledge.org/ParsingLs) to parse the output of `ls`. You should probably look into either using `find` or simple shell globbing to get your list of files to process. Extensive further reading on the subject can be found [here](https://unix.stackexchange.com/questions/128985/why-not-parse-ls). Further, what specifically do you mean by 'last' file in the directory? Most recent? Last lexically? Last in character sort order? Last modified? What if this 'last' file is a directory? – DopeGhoti Sep 13 '17 at 16:33
  • if you're using ls to get the most recent or oldest file, there are also other Q's on here for doing that in various shells – Jeff Schaller Sep 13 '17 at 16:34
  • Then you're still parsing `ls`, which is a bad idea that should make you feel bad. – DopeGhoti Sep 13 '17 at 16:36
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    Did you mean to say `ls ~/Pictures/*` there? Otherwise you're getting an ls of ~/Pictures and of * – Jeff Schaller Sep 13 '17 at 16:39

1 Answers1

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From what I gather from your script, you're reversing the output of ls and selecting the first item. Here's a different way to do that with bash:

files=(~/Pictures/*)
nomacs "${files[-1]}"

This fills an array with the glob expansion of ~/Pictures/* then passes the last element to the nomacs program.

Jeff Schaller
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