change file name in bash

khaled al-sowadi · 06-20-2013, 07:08 AM

dears.

i have some files come to my server (linx)
these files came with ;1 For example (TTFILE006057;1). the ;1 i don't need it.
so i made a script for it
rename.sh

#!/bin/bash

for i in rename.sh;
do mv "/oracledb/mediation/khaled/TTFILE006057;1" "/oracledb/mediation/khaled/TTFILE006057"
done

it's working but there is a lot of files with same beginning but with different end.
for example (TTFILEXXXXXX;1) the xxxxxx is changing number.
so can any one modif it please.

and i want this script keep working all time and work as loop.

also i want to add the file name after changeing to another .txt file

please help

grail · 06-20-2013, 08:14 AM

hmmm ... what is the purpose of your for loop? As it stands it has no use as the move (mv) command does not call the 'i' variable and you are looping based on the name of the script you are in.

You can maybe see that this is not of any real use to you.

If you assume the location does not change then you can actually call your loop with the path to your files and then call the move command and reference your variable as it will be the name
of your file at the end of the path you list. Then you can alter variable to remove the end portion, for this I would suggest parameter substitution, found here (look for the section that refers to % and %%)

Let us know how you go?

NevemTeve · 06-20-2013, 08:41 AM

Use utility find to find the files in question:

Code:

find path -name 'TTFILE*;1' | while read oldname; do
(process one file)
done

(For extreme filenames:

Code:

find . -name 'TTFILE*;1' -print0 |  while read -d '' -r oldname; do
...
done

)

Firerat · 06-20-2013, 08:53 AM

I prefer grail's hint

Code:

path="/oracledb/mediation/khaled"
ext="\;1"
for i in $path/*$ext;do
    ...
done

NevemTeve · 06-20-2013, 09:38 AM

Off: Try it with lots of files.

grail · 06-20-2013, 11:26 AM

Quote:

Originally Posted by NevemTeve

Off: Try it with lots of files.

I am curious, why would the number of files make any difference to the for loop??

NevemTeve · 06-21-2013, 04:23 AM

You're right, in this context number of files isn't a problem, it works even when commands like '/bin/echo *' give error message "The parameter or environment lists are too long". So I was wrong, sorry.

David the H. · 06-23-2013, 09:03 AM

The only time I would avoid using shell globbing is in certain cases where the resulting expanded list can end up being longer than the kernel's ARG_MAX setting. But that setting is generally large enough now that it's rather uncommon to encounter it. My current ARG_MAX setting is 2097152, or two megabytes of text.

I'm getting "Argument list too long". How can I process a large list in chunks?
http://mywiki.wooledge.org/BashFAQ/095

That said, however, bash at least appears to be able to safely use globbing patterns with it's own built-ins without limitation. It's only when it has to execute an external application with a direct list of arguments that the ARG_MAX becomes a problem. Since the for loop is a built-in function, bash has no problem looping over even very large lists with it.

e.g. Here's an example of what I get with a huge file list (everything in my /lib, three times over).

Code:

#using bash's built-in printf
$ printf '%s\n' /lib/**/* /lib/**/* /lib/**/*
<A honkin' big list of file names>

#with the external printf
$ /usr/bin/printf '%s\n' /lib/**/* /lib/**/* /lib/**/*
bash: /usr/bin/printf: Argument list too long

#using a for loop
$ for fname in /lib/**/* /lib/**/* /lib/**/*; do echo "$fname"; done
<The big list again>

#Confirm that the size of the list > ARG_MAX:
$ printf '%s\n' /lib/**/* /lib/**/* /lib/**/* | wc -c
2834793

khaled al-sowadi · 06-24-2013, 03:18 AM

i just made the command to read only the 12 frist diget of file name and rename it
i did this bash and it work will

please check

#!/bin/bash
cd /oracledb/mediation/md_instance/dataProcessors/DataProcessorBS/runContainer/data/input_isc3
for x in `ls TTFILE*\;1`
do
mv $x ${x:0:12} ;
done

NevemTeve · 06-24-2013, 04:50 AM

Please use [code] and [/code] tags. (You can edit your post if you use the [Edit] button.)

Then replace the cycle:

Code:

don't: for x in `ls TTFILE*\;1`
do:    for x in TTFILE*\;1

Also you can be more flexible in renaming:

Code:

mv -- "$x" "${x%;1}"

David the H. · 06-24-2013, 11:18 AM

What NevemTeve posted. But to clarify why, as written your loop demonstrates three common pitfalls:

1) Don't Read Lines With For! for loops are safe to use with globbing patterns, but the output of commands or files needs to be processed with a while+read loop.

2) Don't parse ls for filenames or metadata. Not only is it difficult to safely and correctly read the output, but it's also just plain redundant in this case. The shell is the one that's producing the list of filenames with the globbing pattern, and ls is simply acting here as an unnecessary and less-efficient form of echo/printf.

3) QUOTE ALL OF YOUR VARIABLE EXPANSIONS.

http://mywiki.wooledge.org/Arguments
http://mywiki.wooledge.org/WordSplitting
http://mywiki.wooledge.org/Quotes

This mostly relates to how the shell processes whitespace and breaks up strings into their final arguments. This is the main problem behind point one as well.

And to finish it off, one more suggestion:

4) $(..) is highly recommended over `..`.