Need if statement to run a task only if number of files in the directory are greater than 1

linux bash shell-script

5,206

Something like

[ "$(ls -b | wc -l)" -gt 1 ] && { ... your statements ... }

5,206

jlacroix82

Updated on September 18, 2022

Comments

jlacroix82 over 1 year

I want to write a script, but I want an if statement so it will run only if the number of files in the directory are greater than 1. Is this possible?
- Ozair Kafray almost 12 years
  
  What have you tried? Paste your current script in the question to solicit better answers!
- jlacroix82 almost 12 years
  
  The script is too large to fit in this box. I haven't tried anything yet since I don't have a clue how to do this.
- fmanco almost 12 years
  
  @jlacroix82: You can paste the script in pastebin and put the link here.
- jlacroix82 almost 12 years
  
  Here it is in Pastebin: pastebin.com/4SGFHzVG Please note that I am very sensitive about the script, I don't want anything changed other than the added functionality I'm requesting. I put comments where I want it to check if there are more than one file before doing it.
jlacroix82 almost 12 years

Is there any way to do it with an if statement?
Izzy almost 12 years

That is a (hidden/abbreviated) if..then statement. In full length, it would read if [ "$(ls -b | wc -l)" -gt 1 ]; then ... your statements ...; fi
jlacroix82 almost 12 years

Just tried it, and the <do something here> will not run, even if there are files in the directory.
Izzy almost 12 years

The [ test ] statement may be incorrect: it uses strings (in quotes), but a numeric comparision (-gt). Try replacing that part by [ $nf -gt 1 ] (for a numeric comparision). If you want to do that with strings, it should be [ "$nf" != "0" -a "$nf" != "1" ]. Moreover you could (for test purposes) output the value stored in $nf before the line starting with "if".
jlacroix82 almost 12 years

The statements still run whether there is more than 1 file in the directory or not. Should I increase -gt 1 to -gt 2?
fmanco almost 12 years

@Izzy: That's wrong. The comparisson works with Strings.
fmanco almost 12 years

@jlacroix82: Please. Make sure the current directory is what you want. Don't forget the find is finding files in the current directory. If you want you can change find . to find <directory>. Also you can put the command pwd in your script to know what is your current directory. The script was tested and it works.
Izzy almost 12 years

@criziot: it may work (as sorted alphanumerically, any "string-number" larger than 1 starts with the digit 1 or up), but a) not good style and b) you never know about implementations whether "string -gt string" gets silently converted. The man page of test explicitly states: INTEGER1 -gt INTEGER2: INTEGER1 is greater than INTEGER2. Nothing about strings with "-gt". But don't we argue -- as long as it works ;)
fmanco almost 12 years

@Izzy: Don't forget that -gt always perform arithmetic comparissons. If you try "a" -gt "b" it won't work. But I'm not an expert in bash to discuss this, I wrote it that way because it is how I'm used to see it (like here). And you're right, it is good as long as it works :D
Izzy almost 12 years

@criziot: I'm also used to placing quotes around variables (to avoid trouble with blanks -- regarding those the quote marks are a very good thing), so I thought it was "accidentally". So nevermind, as we agreed: "as long as it works" ;)
fmanco almost 12 years

@jlacroix82: Don't forget this will also count directories, not only files. So if you have two directories inside the current directory the test will succeed even if there are no files.
jlacroix82 almost 12 years

There are no subdirectories at all, unless it's counting ..
jpalecek almost 12 years

@Izzy: There is no difference between "11", 11 and even "1"1 in shell. All are strings with two characters 1.
Izzy almost 12 years

@jpalecek: Thanks, a test confirmed that [ "11" -eq 11 ]. So shell is basically "typeless" -- leaned something new :)
Izzy almost 12 years

@jlacroix82: I just tried if [ $(find . -maxdepth 1 -type f | wc -l) -gt 1 ]; then echo 'Work to do!'; else echo "Go to bed."; fi in a directory with 1 file ("Go to bed.") and with multiple files ("Work to do!") -- so it does work. This is basically the very same construct criziot offered, just "condensed".
fmanco almost 12 years

So the problem is basically what I've told you in my comment. Anyway I've edited my answer so you can see how to use a specific directory, but I'm glad you found a solution.