Bash script to execute command on all files in a d

问题:

Could somebody please provide the code to do the following: Assume there is a directory of files, all of which need to be run through a program. The program outputs the results to standard out. I need a script that will go into a directory, execute the command on each file, and concat the output into one big output file.

For instance, to run the command on 1 file:

$ cmd [option] [filename] > results.out

回答1:

The following bash code will pass $file to command where $file will represent every file in /dir

for file in /dir/*
do
  cmd [option] "$file" >> results.out
done

Example

el@defiant ~/foo $ touch foo.txt bar.txt baz.txt
el@defiant ~/foo $ for i in *.txt; do echo "hello $i"; done
hello bar.txt
hello baz.txt
hello foo.txt

回答2:

How about this:

find /some/directory -maxdepth 1 -type f -exec cmd option {} \; > results.out

• -maxdepth 1 argument prevents find from recursively descending into any subdirectories. (If you want such nested directories to get processed, you can omit this.)
• -type -f specifies that only plain files will be processed.
• -exec cmd option {} tells it to run cmd with the specified option for each file found, with the filename substituted for {}
• \; denotes the end of the command.
• Finally, the output from all the individual cmd executions is redirected to results.out

However, if you care about the order in which the files are processed, you might be better off writing a loop. I think find processes the files in inode order (though I could be wrong about that), which may not be what you want.

回答3:

I'm doing this on my raspberry pi from the command line by running:

for i in *;do omxplayer "$i";done

回答4:

I needed to copy all .md files from one directory into another, so here is what I did.

for i in **/*.md;do mkdir -p ../docs/"$i" && rm -r ../docs/"$i" && cp "$i" "../docs/$i" && echo "$i -> ../docs/$i"; done

Which is pretty hard to read, so lets break it down.

first cd into the directory with your files,

for i in **/*.md; for each file in your pattern

mkdir -p ../docs/"$i"make that directory in a docs folder outside of folder containing your files. Which creates an extra folder with the same name as that file.

rm -r ../docs/"$i" remove the extra folder that is created as a result of mkdir -p

cp "$i" "../docs/$i" Copy the actual file

echo "$i -> ../docs/$i" Echo what you did

; done Live happily ever after

回答5:

Based on @Jim Lewis's approach:

Here is a quick solution using find and also sorting files by their modification date:

$ find  directory/ -maxdepth 1 -type f -print0 | \
  xargs -r0 stat -c "%y %n" | \
  sort | cut -d' ' -f4- | \
  xargs -d "\n" -I{} cmd -op1 {} 

For sorting see:

http://www.commandlinefu.com/commands/view/5720/find-files-and-list-them-sorted-by-modification-time

回答6:

One quick and dirty way which gets the job done sometimes is:

find directory/ | xargs  Command 

For example to find number of lines in all files in the current directory, you can do:

find . | xargs wc -l