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This has been driving me crazy...

I want to list files in a dir and, based on the number interate on all files except the latest one, here is the code snipplet

FILECOUNT=$(ls -lt [dir]*.log | grep -c .log )
for (( c=2; c<=$FILECOUNT; c++ ))
do
FILEDIR=$("ls -1t [dir]*.log | sed -n '$c p'")

I have been having issues with $c interpretation, the format above works but the sed command fails... although entering the last line of the log in the cli works like a charm

 FILECOUNT=24

 (( c=2 ))

 (( c<=24 ))

C is : 2

 'ls -1t [dir]*.log | sed -n '\''2 p'\'''

 line 41: ls -1t [dir]*.log | sed -n '2 p': No such file or directory

any help would be greatly appreciated!

the [dir] is obviously a valid directory

AdminBee
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Jay
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    Please consider switching to a shell such as `zsh` where you can order and select files by modification time using *glob qualifiers* ex. `for f in dir*.log(Om[1,-2]); do` or `for f in dir*.log(om[2,-1]); do`. See [Why *not* parse `ls` (and what to do instead)?](https://unix.stackexchange.com/questions/128985/why-not-parse-ls-and-what-to-do-instead) – steeldriver Jun 02 '21 at 12:55

1 Answers1

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The primary issue you have is that you put everything in the command substitution in double-quotes:

FILEDIR=$("ls -1t [dir]*.log | sed -n '$c p'")

This would instruct the shell to locate an executable file with verbatim name ls -1t [dir]*.log | sed -n '$c p'" and no arguments, as opposed to executing the command ls with options -1t and operand [dir]*.log whose output is to be piped to the executable sed with option -n and argument '$c p'. Try to remove the double-quotes, as in

FILEDIR=$(ls -1t [dir]*.log | sed -n '$c p')

However then you will face the issue that the variable expansion is disabled in your single-quoted sed command. One recommended way is to break the single-quote argument and place the variable in a double-quoted interjection, as in

FILEDIR=$(ls -1t [dir]*.log | sed -n "$c"' p')

Also, I must issue the mandatory warning not to parse the output of ls. ;)

AdminBee
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    @Jay You're welcome :) But as mentioned, you may want to look at methods that don't involve the output of `ls` for future applications - filenames can "legally" contain a lot of crazy characters, some of which (in particular spaces and newlines) will confuse your shell and lead to strange behavior. – AdminBee Jun 02 '21 at 13:16