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Trying to rewrite srm (safely remove): problem with spaces in filenames

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Join Date: Jun 2008

Posts: 182

Reputation: mrboolf will become famous soon enough

Solved Threads: 18

mrboolf

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Junior Poster

Trying to rewrite srm (safely remove): problem with spaces in filenames

Jul 20th, 2008

Hi all.
I am trying to write a "light" version of srm just as an exercise of shell scripting (started today with this ^^" I have to keep it really simple)
Basically it should just search for a file and, if found, ask for a confirmation before deleting it.
Now, it worked fine with /any/directory/you/like/no_spaces_in_the_name.file and I hoped to make it a little less dumb

Here's the code:

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#!/bin/bash
#
#Script to safely remove files (asks confirmation)
#
choice="n"
if [ $# -eq 0 ]
then
echo "srm: missing argument."
echo "Syntax: $0 file_to_safely_delete."
exit 1
fi
filename=$1
if [ $# -gt 1 ]
then
filename="'$@'"
echo "$filename"
fi
if test -f $filename 
then
echo "$filename found. Are you sure you want to permanently delete it? (y/n)"
read choice
if [ $choice = "y" ] 
then
`rm $filename`
echo "$filename permanently deleted."
else
echo "$filename untouched."
fi
else
echo "$filename not found. Nothing done."
fi

The added part is

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if [ $# -gt 1 ]
then
filename="'$@'"
echo "$filename"
fi
if [ $# -gt 1 ]
then
filename="'$@'"
echo "$filename"
fi

I put in it echo "$filename" for debugging and it shows correctly the string 'name of file with spaces'
The error I receive is @ this line: if test -f $filename
It prints out this: line 18: test: too many arguments After I call it with srm just a try
I am just blind on why it doesn't work... any idea?
Anticipate thanks

p.s.
I have not yet find anything abount problems with spacing in shell scripting, but ¿strangely? if I indent the code like I'm used to with c/c++ it complains a lot so I'm not doing it at all. It's not urgent but I think I'm simply missing something obvious, so I'll be very grateful to anyone who'll give a sort of explanation ^^"

p.p.s.
as usual sorry for my english

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Join Date: Dec 2005

Posts: 5,850

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Salem

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Void main'ers are DOOMed

Re: Trying to rewrite srm (safely remove): problem with spaces in filenames

Jul 20th, 2008

Try putting the filename variable in quotes in other places as well.

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Join Date: Jun 2008

Posts: 182

Reputation: mrboolf will become famous soon enough

Solved Threads: 18

mrboolf

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Junior Poster

Re: Trying to rewrite srm (safely remove): problem with spaces in filenames

Jul 20th, 2008

I made these changes after your suggestion (red lines had quotes added around $filename)

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#!/bin/bash
#
#Script to safely remove files (asks confirmation)
#
choice="n"
if [ $# -eq 0 ]
then
echo "srm: missing argument."
echo "Syntax: $0 file_to_safely_delete."
exit 1
fi
filename=$1
if [ $# -gt 1 ]
then
filename="'$@'"
echo "$filename"
fi
if test -f "$filename" 
then
echo "$filename found. Are you sure you want to permanently delete it? (y/n)"
read choice
if [ $choice = "y" ] 
then
`rm "$filename"`
echo "$filename permanently deleted."
else
echo "$filename untouched."
fi
else
echo "$filename not found. Nothing done."
fi

Now it doesn't complains, but it's malfunctioning: it enters the last else case even if "just a try" actually exists as a file :?

I can't imagine neither the cause nor the solution of this problem...

Actual situation:

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ludovico@ludovico-laptop:~/Desktop$ srm just a try
'just a try'
'just a try' not found. Nothing done.
ludovico@ludovico-laptop:~/Desktop$ srm just a try
'just a try'
'just a try' not found. Nothing done.

Ok, putting single quotes ' ' around the file name when calling the script made it work properly. I still don't understand why... I thought that

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...
filename="'$@'"
...

would have done the job. Any explanation? Btw, thank you all, I'm just curious now ^^

Last edited by mrboolf; Jul 20th, 2008 at 9:06 am. Reason: Solved, but still not understanding how

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Join Date: Oct 2007

Posts: 399

Reputation: eggi will become famous soon enough

Solved Threads: 47

eggi

Offline

Posting Whiz

Re: Trying to rewrite srm (safely remove): problem with spaces in filenames

Jul 20th, 2008

Hey There,

Inside the double quotes, in your test statement, the single quotes are being treated as literal characters in the value of the filename variable:

If you just change

•

if test -f filename="'$@'"

•

if test -f filename="$@"

you should be all set

Hope that helps

, Mike

Last edited by eggi; Jul 20th, 2008 at 11:48 pm. Reason: typo

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