[N00B] Generate filenames from a file!

Dee-ehn · 12-23-2004, 05:01 AM

Hi,

I have a file (let's call it a.gif). And I have a text file with a list of names in it.
What I need is some kind of script that will make a copies of a.gif; each new name of a.gif will correspond to 1 line from that text file.

So I get for instance 5000 copies of a.gif, called house.gif, car.gif, tux.gif and so on.

How can I realise this? I think a simple BASH script can do this, but I do not have a clue how

Thanx in advnace!

bigearsbilly · 12-23-2004, 05:09 AM

seems a strange thing to want to do!

what for?

billy

Hko · 12-23-2004, 05:21 AM

Quote:

Originally posted by bigearsbilly
seems a strange thing to want to do!

I agree. Anyways, here goes:

Example list file "yourlist.txt":

Code:

blabla.gif
/home/hko/dummy/b.gif
/home/hko/dummy/c.gif
/home/hko/dummy/d.gif
/tmp/dummy/aaa.gif
/tmp/dummy/bbb.gif
/tmp/dummy/ccc.gif

The (bash) script "multicopy.sh":

Code:

#!/bin/bash

# This script copies SRCFILE (see below) to all
# file names listed in LISTFILE.
#
# When a directory in LISTFILE does not exist yet,
# it will be created.

SRCFILE="a.gif"
LISTFILE="yourlist.txt"

while read NEWFILE ; do
	mkdir -p "${NEWFILE%/*}"
	cp -v $SRCFILE $NEWFILE
done <"$LISTFILE"
exit 0

bigearsbilly · 12-23-2004, 05:24 AM

Very nice, neat bit of code Hko.
let's hope it will be used for a good cause!

regards,
billy

Dee-ehn · 12-23-2004, 05:48 AM

Hko: many thanx, I'll be trying it soon!

What I do need it for? For a website that I am devoping. I'm, working with a huge set of items that has to be accomponied with the same banner everytime. When I do this the banner has the same name as the variable for the showed item so I only need 1 variable. In that way, if we want to, we can later change individual banners without having to rewrite the entire code; for now we'll just use one banner... that's why

homey · 12-23-2004, 02:49 PM

Quote:

Very nice, neat bit of code Hko.

I agree but am confused as why are you making all of those directories?

The way it looks to me is the name file has a bunch of names ....

list.txt

Code:

car
house
train
tux
fish
bear
truck

and your script would be like this ...

Code:

#!/bin/bash
# This script copies SRCFILE (see below) to all
# file names listed in LISTFILE.

SRCFILE="a.gif"
LISTFILE="list.txt"

while read NEWFILE ; do
	cp -v $SRCFILE ${NEWFILE}.gif
done <"$LISTFILE"
exit 0

Hko · 12-23-2004, 05:09 PM

Quote:

Originally posted by homey
I agree but am confused as why are you making all of those directories?

The way it looks to me is the name file has a bunch of names ....

It's just a feature,
With your list.txt my script wil have the same result.
I was more or less expecting some follow-up question like: "how to copy the files to other directories?", and possibly next: "how to copy them to a directory that doesn't exist yet?".

homey · 12-23-2004, 07:27 PM

Cool!

I wonder if there is a performance advantage to using this ...
done <"$LISTFILE"

instead of this ....
cat $LISTFILE |\
while read NEWFILE ; do

or is it just a method which you prefer?

dustu76 · 12-24-2004, 03:19 AM

Hko, since you seem to be one who likes to take care of the widest range of scenarios, I thought I would point something to you:

Code:

$ ls -l
total 0
-rw-r--r--   1 supmis   supmis         0 Dec 24 14:35  asdf  asdf
-rw-r--r--   1 supmis   supmis         0 Dec 24 14:35 a
-rw-r--r--   1 supmis   supmis         0 Dec 24 14:35 asdf asasd23
-rw-r--r--   1 supmis   supmis         0 Dec 24 14:35 b
$ ls -1 > /tmp/a.txt
$ cat /tmp/a.txt
 asdf  asdf
a
asdf asasd23
b
$ while read fname ; do
> echo "${fname}"
> done < /tmp/a.txt
asdf  asdf
a
asdf asasd23
b
$ for fname in "$(cat /tmp/a.txt)" ; do
> echo "${fname}"
> done
 asdf  asdf
a
asdf asasd23
b
$

The point of this code is the leading space for filename " asdf asdf". In this case, for seems to be a better choice. This happends on those extremely rare occassions when the filename has leading space(s).

HTH.

Hko · 12-24-2004, 05:57 AM

Quote:

Originally posted by dustu76
Hko, since you seem to be one who likes to take care of the widest range of scenarios,

Heh..well yes, I guess so...

Quote:

I thought I would point something to you:

[..snip code..]

The point of this code is the leading space for filename " asdf asdf". In this case, for seems to be a better choice. This happends on those extremely rare occassions when the filename has leading space(s).

Good point! Though, as you say, it's a rare occasion. A bug that counts anyways. Thanks.

I wonder if it could be done right without the "for F in $(cat file.txt) ; do" construction. Generally I don't like this very much, because it can yield in a huge command line being executed.

bigearsbilly · 12-24-2004, 06:23 AM

or

DATA

Code:

billym.primadtpdev>cat ~/1
  asdf  asdf
a
asdf asasd23
b

SCRIPT

Code:

billym.primadtpdev>cat ~/2

IFS=
while read file
    do
        echo "file=[$file]"
done

RESULT

Code:

billym.primadtpdev>bash ~/2 < ~/1
file=[  asdf  asdf]
file=[a]
file=[asdf asasd23]
file=[b]

Hko · 12-24-2004, 07:21 AM

Ah, IFS,...right. Thanks.

Dee-ehn · 12-28-2004, 10:06 AM

Thanx, it worked out great!