Bash脚本打印文件列表

Question

Its my first time to use BASH scripting and been looking to some tutorials but cant figure out some codes. I just want to list all the files in a folder, but i cant do it. Heres my code so far.

#!/bin/bash
# My first script
echo "Printing files..."
FILES="/Bash/sample/*"

for f in $FILES
do
    echo "this is $f"
done

and here is my output..

Printing files... this is /Bash/sample/*

What is wrong with my code?

Answer 1

You misunderstood what bash means by the word "in". The statement for f in $FILES simply iterates over (space-delimited) words in the string $FILES , whose value is "/Bash/sample" (one word). You seemingly want the files that are "in" the named directory, a spatial metaphor that bash's syntax doesn't assume, so you would have to explicitly tell it to list the files.

for f in `ls $FILES`         # illustrates the problem - but don't actually do this (see below)
...

might do it. This converts the output of the ls command into a string, "in" which there will be one word per file.

NB: this example is to help understand what "in" means but is not a good general solution. It will run into trouble as soon as one of the files has a space in its name—such files will contribute two or more words to the list, each of which taken alone may not be a valid filename. This highlights (a) that you should always take extra steps to program around the whitespace problem in bash and similar shells, and (b) that you should avoid spaces in your own file and directory names, because you'll come across plenty of otherwise useful third-party scripts and utilities that have not made the effort to comply with (a). Unfortunately, proper compliance can often lead to quite obfuscated syntax in bash.

Answer 2

I think problem in path " /Bash/sample/* ".

U need change this location to absolute, for example:

/home/username/Bash/sample/*

Or use relative path, for example:

~/Bash/sample/*

On most systems this is fully equivalent for:

/home/username/Bash/sample/*

Where username is your current username, use whoami to see your current username.

Best place for learning Bash: http://www.tldp.org/LDP/abs/html/index.html

Answer 3

This should work:

echo "Printing files..."
FILES=(/Bash/sample/*) # create an array.
                       # Works with filenames containing spaces.
                       # String variable does not work for that case.

for f in "${FILES[@]}" # iterate over the array.
do
    echo "this is $f"
done

& you should not parse ls output .

Answer 4

Take a list of your files)

If you want to take list of your files and see them:

    ls                           ###Takes list###
    ls -sh                       ###Takes list + File size###
    ...

If you want to send list of files to a file to read and check them later:

    ls > FileName.Format         ###Takes list and sends them to a file###
    ls > FileName.Format         ###Takes list with file size and sends them to a file###