trying to link commands...looping

compused · 12-21-2008, 08:28 PM

Hello there...
Could someone please help?

I am wanting a script to see if there are any .tif files in a directory and if so, to run the imagemagick program to convert them to .gif and then to delete the .tif originals. I can do the imagemagick conversion manually via command line. I am calling the script via cron, every one minute. But it seems to be looping and results in the computer crashing. Probably one minute is too frequent for a start...could someone please check this script. I put it together using examples found. I am sure there are some syntax errors. OS is centos 4. something

Thanks for anyone who can help.
Michael

#!/bin/sh
for file in $(ls /home/server_dir/_scan/*tif)
do
[ -s $file ] || continue

while true
do
ps -ef | grep /usr/local/bin/convert |grep -v grep
if test $? -ne 0
then
for i in /home/server_dir/_scan/*tif; do /usr/local/bin/convert $i /home/server_dir/_scan/$(basename $i tif)gif; done > /dev/null 2>&1
find /home/server_dir/_scan/*tif -exec /bin/rm -f {} \; > /dev/null 2>&1
else
: do nothing
fi

sleep 15
done
:

vladmihaisima · 12-21-2008, 09:05 PM

Your script I think is a bit too complex. How about something like:

Code:

#!/bin/sh
for file in $(ls /home/server_dir/_scan/*tif) do
	/usr/local/bin/convert $file /home/server_dir/_scan/$(basename $file tif)gif; 
	rm $file
done

(please use code tag when you post code).

Of course, with the above script I assume that the script finishes until next time it is started. You could avoid that somehow, but I would say it is easier just to increase the time between starts (to, let's say 5 minutes or something).

PS: your script can delete sometimes more files... When you do the find for tif you could find 'new' files, not processed by your script. My simple one doesn't have this problem..

compused · 12-22-2008, 12:25 AM

Thanks very much..this is the code I used:

Code:

#!/bin/sh
for file in $(ls /home/server_dir/_scan/*tif); do /usr/local/bin/convert $file /home/server_dir/_scan/dddd/$(basename $file tif)gif; > /dev/null 2>&1
	rm $file
done

It worked but gave error messages, esp in relation to the rm command (which failed to rm), and the "> /dev/null 2>&1" command failed to suppress output (line spaces inserted by myself):

Quote:

convert: unable to open image `20081212044800.tif': No such file or directory @ magick/blob.c/OpenBlob/2418.
convert: missing an image filename `/home/server_dir/_scan/dddd/20081212044800.gif' @ wand/convert.c/ConvertImageCommand/2710.
: ambiguous redirectf_new2.sh: line 2: 1
rm: cannot remove `20081212044800.tif\r': No such file or directory
convert: unable to open image `/home/server_dir/_scan/sarah': No such file or directory @ magick/blob.c/OpenBlob/2418.
convert: missing an image filename `/home/server_dir/_scan/dddd/sarahgif' @ wand/convert.c/ConvertImageCommand/2710.
: ambiguous redirectf_new2.sh: line 2: 1
rm: cannot remove `/home/server_dir/_scan/sarah\r': No such file or directory

convert: unable to open image `byrnes': No such file or directory @ magick/blob.c/OpenBlob/2418.
convert: missing an image filename `/home/server_dir/_scan/dddd/byrnesgif' @ wand/convert.c/ConvertImageCommand/2710.
: ambiguous redirectf_new2.sh: line 2: 1
rm: cannot remove `byrnes\r': No such file or directory

convert: unable to open image `20081202032924.tif': No such file or directory @ magick/blob.c/OpenBlob/2418.
convert: missing an image filename `/home/server_dir/_scan/dddd/20081202032924.gif' @ wand/convert.c/ConvertImageCommand/2710.
: ambiguous redirectf_new2.sh: line 2: 1
rm: cannot remove `20081202032924.tif\r': No such file or directory
: ambiguous redirectf_new2.sh: line 2: 1
rm: cannot remove `/home/server_dir/_scan/sh....20081124033036.tif\r': No such file or directory
[root@asterisk1 ~]#

vladmihaisima · 12-22-2008, 05:19 AM

Do you have spaces in your filenames ? If so this is one problem.

The problem with the output is that you put a ";" before the two redirects.

This should work then:

Code:

#!/bin/sh
IFS="\n"
for file in $(ls -1 /home/server_dir/_scan/*tiff); do
  /usr/local/bin/convert "$file" "/home/server_dir/_scan/$(basename "$file" tiff)gif" ;
  rm "$file";
done

IFS means internal field separator (I put it as newline). The "ls -1" puts each file on a different line. So, now, file will contain the correct file name with spaces. Because of this you need a lot of extra quoting.

To supress the output I would suggest putting ">/dev/null 2>&1" in the crontab....

compused · 12-22-2008, 06:19 AM

Thanks!
Will see how I go!
Michael

GazL · 12-22-2008, 08:09 AM

The above solutions have a few issues.

Using a for with a ls can be a bit dodgy as it's all done through command line expansion which can fail if the expansion exceeds the maximum command line length. e.g. a large number of files.
They don't ensure that the matched filename is a regular file and not just a directory with .tiff on the end of its name.
Worst of all, no check for a successful conversion is done before removing the original file, which could result in data loss!

The following is a slightly more robust solution, which avoids the above issues and will also cope with filenames with spaces in them without having to mess with $IFS.

Code:

#!/bin/bash
#
# Directory to process
  CONVDIR='/home/server_dir/_scan/'    

find "$CONVDIR" -type f -name "*.tiff" | while read filename
  do
    /usr/local/bin/convert "$filename" "${filename%.tiff}.gif" && \
      rm "$filename"
  done

As is, it will process all sub-directories within the directory. If you want it to only process the directory passed and ignore sub-directories add -maxdepth 1 to the find command.

compused · 12-22-2008, 02:58 PM

Thanks very much Gazl!
The script does need to be reliable!
Rgds
Michael

compused · 12-22-2008, 09:20 PM

Hi I get this error message:

Quote:

[root@asterisk1 ~]# sh /home/scripts/tif2gif_new2.sh
: command not foundif_new2.sh: line 7:
/home/scripts/tif2gif_new2.sh: line 15: syntax error near unexpected token `done'
/home/scripts/tif2gif_new2.sh: line 15: `done'

for this code:
(some comment lines removed for the copy paste)

Code:

#!/bin/sh

# Directory to process
  CONVDIR='/home/server_dir/_scan/'    

find "$CONVDIR" -type f -name "*.tif" | while read filename
  do
    /usr/local/bin/convert "$filename" "${filename%.tif}.gif" && \
      rm "$filename"
done

any ideas?
Michael

GazL · 12-23-2008, 05:00 AM

Quote:

Originally Posted by compused

Hi I get this error message:

for this code:
(some comment lines removed for the copy paste)

Code:

#!/bin/sh

# Directory to process
  CONVDIR='/home/server_dir/_scan/'    

find "$CONVDIR" -type f -name "*.tif" | while read filename
  do
    /usr/local/bin/convert "$filename" "${filename%.tif}.gif" && \
      rm "$filename"
done

any ideas?
Michael

it may be that the ${filename%.tif}.gif syntax isn't supported by whatever shell /bin/sh is on your system. If you change it back to /bin/bash it should work.

PS. If you have to stick with the /bin/sh shell then you can try the following instead.

Code:

newfile=$( echo "$filename" | sed 's/.tif$/.gif/' )
/usr/local/bin/convert "$filename" "$newfile" && \