Friday, October 15, 2010

Linux / UNIX Delete or Remove Files With Inode Number


An inode identifies the file and its attributes such as file size, owner, and so on. A unique inode number within the file system identifies each inode. But, why to delete file by an inode number? Sure, you can use rm command to delete file. Sometime accidentally you creates filename with control characters or characters which are unable to be input on a keyboard or special character such as ?, * ^ etc. Removing such special character filenames can be problem. Use following method to delete a file with strange characters in its name:
Please note that the procedure outlined below works with Solaris, FreeBSD, Linux, or any other Unixish oses out there:

Find out file inode

First find out file inode number with any one of the following command:
stat {file-name}
OR
ls -il {file-name}

Use find command to remove file:

Use find command as follows to find and remove a file:
find . -inum [inode-number] -exec rm -i {} \;
When prompted for confirmation, press Y to confirm removal of the file.

Delete or remove files with inode number

Let us try to delete file using inode number.
(a) Create a hard to delete file name:
$ cd /tmp
$ touch "\+Xy \+\8"
$ ls

(b) Try to remove this file with rm command:
$ rm \+Xy \+\8
(c) Remove file by an inode number, but first find out the file inode number:
$ ls -ilOutput:
981956 drwx------  3 rajat admin 4096 2010-10-15 15:05 gconfd-viv
981964 drwx------  2 rajat admin 4096 2010-10-15 15:05 keyring-pKracm
982049 srwxr-xr-x  1 rajat admin    0 2010-10-15 15:05 mapping-viv
981939 drwx------  2 rajat admin 4096 2010-10-15 15:31 orbit-viv
981922 drwx------  2 rajat admin 4096 2010-10-15 15:05 ssh-cnaOtj4013
981882 drwx------  2 rajat admin 4096 2010-10-15 15:05 ssh-SsCkUW4013
982263 -rw-r--r--  1 rajat admin    0 2010-10-15 15:49 \+Xy \+\8
Note: 982263 is inode number.
(d) Use find command to delete file by inode:
Find and remove file using find command, type the command as follows:
$ find . -inum 982263 -exec rm -i {} \;
Note you can also use add \ character before special character in filename to remove it directly so the command would be:
$ rm "\+Xy \+\8"
If you have file like name like name "2009/12/31" then no UNIX or Linux command can delete this file by name. Only method to delete such file is delete file by an inode number. Linux or UNIX never allows creating filename like 2009/12/31 but if you are using NFS from MAC OS or Windows then it is possible to create a such file.



Remove Files and Directories with Special Characters

Today is going to be a practical tip. If you're managing many Unix/Linux systems, sooner or later you come across files with special characters – they can't be deleted with rm command using standard approach and require a bit of trickery to be successfully removed.

Examples of files with special characters

Any language apart from English will probably have special characters in the alphabet, but for the purpose of today's exercise I'll give you more standard examples: files starting with dash (-) and hash (#) characters:
rajat-linux$ ls -al
-rw-r--r-- 1 rajat admin    0 Sep 25 05:50 #try
-rw-r--r-- 1 rajat admin    0 Sep 25 05:48 -try
Now, if you try to access these files or remove them, you will get errors:
rajat-linux$ cat -try
cat: invalid option -- r
Try `cat --help' for more information.
rajat-linux$ rm -try
rm: invalid option -- t
Try `rm ./-try' to remove the file `-try'.
Try `rm --help' for more information.
These errors happen because commands treat file names as command line options because they start with dash (-).
With filenames starting with hash (#), you'll get a different kind of error: your Unix shell will treat the rest of a filename (and anything that might follow it) as a comment because hashes are used to do it in shell scripts. That's why your cat command will not show any error but will not finish until you Ctrl+C it:
rajat-linux$ cat #try
… and if you try removing such a file, you'll get a complaint from the rm command about missing command line parameters – because of the hash (#) sign, rm command receives no text as a parameter:
rajat-linux$ rm #try
rm: missing operand
Try `rm --help' for more information.

How to remove a file when filename starts with dash (-)

First I'm gonna show you how to make your Unix shell interpret any filename directly instead of trying to analyze it as a set of command line options.
To make command ignore the leading dash (-) in a filename, use the — command line option:
rajat-linux$ rm -- -try
As you can see, our file is gone:
rajat-linux$ ls -al
-rw-r--r-- 1 rajat admin    0 Sep 25 05:50 #try

Using backslash to escape special characters in a filename

Another option we have is to use a backslash (\), which will make shell interpreter ignore the special functionality of a character which immediately follows it. To escape the hash (#) our second file has, we should therefore do the following:
rajat-linux$ rm \#try
Interesting to know: bash shell has an auto-completion functionality built in. When you type a filename, just press Tab key to make it auto-complete the name for you. Speaking of special characters in particular, quite a few of them are recognized by auto-completion and get escaped automatically.
So, if you start typing:
rajat-linux $ rm #t
… and then press Tab, bash will not only auto-complete the name, but escape the leading hash (#):
rajat-linux $ rm \#try
There's a few more tricks you can use for escaping special characters, but they're worth a separate post, so stay tuned! Until then, enjoy getting rid of annoying files with special characters in filenames!

Thursday, October 14, 2010

Xoops Installation on Cent OS/Fedora /RedHat with LAMP

What XOOPS stands for
XOOPS is an acronym of eXtensible Object Oriented Portal System. Though started as a portal system, XOOPS is in fact striving steadily on the track of Content Management System. It can serve as a web framework for use by small, medium and large sites.

A lite XOOPS can be used as a personal weblog or journal. For this purpose, you can do a standard install, and use its News module only. For a medium site, you can use modules like News, Forum, Download, Web Links etc to form a community to interact with your members and visitors. For a large site as an enterprise one, you can develop your own modules such as eShop, and use XOOP's uniform user management system to seamlessly integrate your modules with the whole system.



# rpm -Uhv http://apt.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

#yum install mysql mysql-server httpd php php-mysql php-gd php-imap php-ldap php-odbc php-pear php-xml php-xmlrpc phpmyadmin


#service httpd start


#service mysqld start


#/usr/bin/mysqladmin -u root password 'new-password'


#vi /etc/httpd/conf.d/phpMyAdmin.conf

http://youdomain.com/phpmyadmin



#wget http://sourceforge.net/projects/xoops/files/XOOPS%20Core%20%28stable%20releases%29/XOOPS%202.4.5/xoops-2.4.5.zip/download

#unzip xoops-2.4.5.zip -d /var/www/html/

#chmod 777 /var/www/html/xoops-2.4.5/htdocs/mainfile.php
#chmod 777 /var/www/html/xoops-2.4.5/htdocs/mainfile.dist.php
#chmod 777 /var/www/html/xoops-2.4.5/htdocs/uploads/
#chmod  777 /var/www/html/xoops-2.4.5/htdocs/include/license.php
#chmod 777 var/www/html/xoops-2.4.5/htdocs/xoops_data/caches/smarty_*

open firefox

http://yourdomain.com/xoops-2.4.5/htdocs/install/index.php








Wednesday, October 13, 2010

ffmpeg commands

FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec – the leading audio/video codec library. FFmpeg is free software and is licensed under the LGPL or GPL depending on your choice of configuration options.
FFmpeg supports most of the popular formats, we don’t need to worry a lot about that. Formats supported by FFmpeg include MPEG, MPEG-4 (Divx), ASF, AVI, Real Audio/Video and Quicktime. To see a list of all the codecs/formats supported by FFmpeg, run the following command:

ffmpeg -formats

1. X11 grabbing

FFmpeg can grab the X11 display.
ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable.
ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable. 10 is the x-offset and 20 the y-offset for the grabbing.
ffmpeg -f x11grab -r 25 -s 800x600 -i :0.0 /tmp/outputFile.mpg

2. Convert Pictures To Movie

First, rename your pictures to follow a numerical sequence. For example, img1.jpg, img2.jpg, img3.jpg,… Then you may run:
ffmpeg -f image2 -i img%d.jpg /tmp/a.mpg
Notice that `%d’ is replaced by the image number.
`img%03d.jpg' means the sequence `img001.jpg', `img002.jpg', etc…
If you have large number of pictures to rename, you can use the following command to ease the burden. The command, using the bourne shell syntax, symbolically links all files in the current directory that match *jpg to the `/tmp' directory in the sequence of `img001.jpg', `img002.jpg' and so on.
x=1; for i in *jpg; do counter=$(printf %03d $x); ln "$i" /tmp/img"$counter".jpg; x=$(($x+1)); done
If you want to sequence them by oldest modified first, substitute $(ls -r -t *jpg) in place of *jpg.
Then run:
ffmpeg -f image2 -i /tmp/img%03d.jpg /tmp/a.mpg
The same logic is used for any image format that ffmpeg reads.

3. Video Conversions

Quick and dirty convert to flv
ffmpeg -i inputfile.mp4 outputfile.flv
This converts any media ffmpeg handles to flash. It would actually convert anything to anything, it’s based on the file extension. It doesn’t do ANY quality control, sizing, etc, it just does what it thinks is best.
Convert .flv to .3gp
ffmpeg -i file.flv -r 15 -b 128k -s qcif -acodec amr_nb -ar 8000 -ac 1 -ab 13 -f 3gp -y out.3gp
Download YouTube videos as .flv and convert them to .3gp for your mobile phone.
Convert AVI to iPhone MP4
ffmpeg -i [source].avi -f mp4 -vcodec mpeg4 -b 250000 -s 480?320 -acodec aac -ar 24000 -ab 64 -ac 2 [destination].mp4
for 4:3 aspect:
ffmpeg -i source-xvid.avi -s 480x320 -aspect 4:3 -b 768k -ab 64k -ar 22050 -r 30000/1001 OUT.mp4
for 16:9:
ffmpeg -i source-xvid.avi -s 480x320 -aspect 16:9 -b 768k -ab 64k -ar 22050 -r 30000/1001 OUT.mp4
Create a video that is supported by youtube:
ffmpeg -i mymovie.mpg -ar 22050 -acodec libmp3lame -ab 32K -r 25 -s 320x240 -vcodec flv
mytarget.flv
Takes an mpeg video and coverts it to a youtube compatible flv file.
The -r 25 sets the frame rate for PAL, for NTSC use 29.97

4. Audio Conversion

Convert RM file to mp3
ffmpeg -i input.rm -acodec libmp3lame -ab 96k output.mp3
Adjust the bitrate (-ab) as necessary. If omitted FFmpeg will use a default of 64 kb/s.
Converting WMV to MP3 using FFMPEG
ffmpeg -i audio1.wmv audio1.mp3
This will convert audio1.wmv file to audio1.mp3
Converting WMV to FLV using FFMPEG

ffmpeg -i audio1.wmv audio1.flv
This will convert audio1.wmv file to audio1.flv, this will generate only audio content
Converting AMR to MP3 using FFMPEG

ffmpeg -i audio1.amr -ar 22050 audio1.mp3
This will convert audio1.amr file to audio1.mp3 having audio rate 22.05 Khz
Converting aac to mp3 using FFMPEG

ffmpeg -i audio1.aac -ar 22050 -ab 32 audio1.mp3
This will convert audio1.aac to audio1.mp3 having audio rate 22.05 Khz and Audio BitRate 32Khz
Converting aac to mp3 using FFMPEG with MetaData

ffmpeg -i audio1.aac -ar 22050 -ab 32 -map_meta_data audio1.mp3:audio1.aac audio1.mp3
This will convert audio1.aac to audio1.mp3 having audio rate 22.05 Khz and Audio BitRate 32Khz and will copy the meta data from .aac file to .mp3 file

5. Audio Extraction

ffmpeg -i video.avi -f mp3 audio.mp3
Dumping Audio stream from flv (using ffmpeg)
ffmpeg -i input.flv -f mp3 -vn -acodec copy ouput.mp3

6. Record Audio and Video from webcam

To record video run ffmpeg with arguments such as these:
ffmpeg -f video4linux2 -s 320x240 -i /dev/video0 out.mpg
To record both audio and video run ffmpeg with arguments such as these:
ffmpeg -f oss -i /dev/dsp -f video4linux2 -s 320x240 -i /dev/video0 out.mpg

7. Copy Only A Part Of Video

Cut out a piece of film from a file. Choose an arbitrary length and starting time.
ffmpeg -vcodec copy -acodec copy -i orginalfile -ss 00:01:30 -t 0:0:20 newfile
-vcodec, you choose what video codec the new file should be encoded with. Run ffmpeg -formats E to list all available video and audio encoders and file formats.
copy, you choose the video encoder that just copies the file.
-acodec, you choose what audio codec the new file should be encoded with.
copy, you choose the audio encoder that just copies the file.
-i originalfile, you provide the filename of the original file to ffmpeg
-ss 00:01:30, you choose the starting time on the original file in this case 1 min and 30 seconds into the film
-t 0:0:20, you choose the length of the new film
newfile, you choose the name of the file created.

8. Join Multiple Video Files

A few multimedia containers (MPEG-1, MPEG-2 PS, DV) allow to join video files by merely concatenating them.
Hence you may concatenate your multimedia files by first transcoding them to these privileged formats, then using the humble cat command (or the equally humble copy under Windows), and finally transcoding back to your format of choice.
mkfifo orig1.mpg
mkfifo orig2.mpg
ffmpeg -i input1.avi -sameq -y orig1.mpg
ffmpeg -i input2.avi -sameq -y orig2.mpg
Merge files
cat orig1.mpg orig2.mpg | ffmpeg -f mpeg -i - -vcodec copy -acodec copy merged.mpg
Merge and convert to avi
cat orig1.mpg orig2.mpg | ffmpeg -f mpeg -i - -sameq -vcodec mpeg4 -acodec libmp3lame merged.avi
Notice that you should either use -sameq or set a reasonably high bitrate for your intermediate and output files, if you want to preserve video quality.
Also notice that you may avoid the huge intermediate files by taking advantage of named pipes, should your platform support it:

9. Removing Synchronization Problems Between Audio and Video

ffmpeg -i source_audio.mp3 -itsoffset 00:00:10.2 -i source_video.m2v target_video.flv
This assumes that there is a 10.2 sec delay between the video and the audio (delayed).
To extract the original video into a audio and video composites look at the command on extracting audio and video from a movie
Here is more information of how to use ffmpeg:
http://www.ffmpeg.org/ffmpeg-doc.html


ffmpeg is a multiplatform, open-source library for video and audio files. Useful and amazing commands covering almost all needs: video conversion, sound extraction, encoding file for iPod or PSP, and more.

Getting infos from a video file
ffmpeg -i video.avi
Turn X images to a video sequence
ffmpeg -f image2 -i image%d.jpg video.mpg
This command will transform all the images from the current directory (named image1.jpg, image2.jpg, etc…) to a video file named video.mpg.
Turn a video to X images
ffmpeg -i video.mpg image%d.jpg
This command will generate the files named image1.jpg, image2.jpg, …
The following image formats are also availables : PGM, PPM, PAM, PGMYUV, JPEG, GIF, PNG, TIFF, SGI.
Encode a video sequence for the iPpod/iPhone
ffmpeg -i source_video.avi input -acodec aac -ab 128kb -vcodec mpeg4 -b 1200kb -mbd 2 -flags +4mv+trell -aic 2 -cmp 2 -subcmp 2 -s 320x180 -title X final_video.mp4
Explanations :
  • Source : source_video.avi
  • Audio codec : aac
  • Audio bitrate : 128kb/s
  • Video codec : mpeg4
  • Video bitrate : 1200kb/s
  • Video size : 320px par 180px
  • Generated video : final_video.mp4
Encode video for the PSP
ffmpeg -i source_video.avi -b 300 -s 320x240 -vcodec xvid -ab 32 -ar 24000 -acodec aac final_video.mp4
Explanations :
  • Source : source_video.avi
  • Audio codec : aac
  • Audio bitrate : 32kb/s
  • Video codec : xvid
  • Video bitrate : 1200kb/s
  • Video size : 320px par 180px
  • Generated video : final_video.mp4
Extracting sound from a video, and save it as Mp3
ffmpeg -i source_video.avi -vn -ar 44100 -ac 2 -ab 192 -f mp3 sound.mp3
Explanations :
  • Source video : source_video.avi
  • Audio bitrate : 192kb/s
  • output format : mp3
  • Generated sound : sound.mp3
Convert a wav file to Mp3
ffmpeg -i son_origine.avi -vn -ar 44100 -ac 2 -ab 192 -f mp3 son_final.mp3
Convert .avi video to .mpg
ffmpeg -i video_origine.avi video_finale.mpg
Convert .mpg to .avi
ffmpeg -i video_origine.mpg video_finale.avi
Convert .avi to animated gif(uncompressed)
ffmpeg -i video_origine.avi gif_anime.gif
Mix a video with a sound file
ffmpeg -i son.wav -i video_origine.avi video_finale.mpg
Convert .avi to .flv
ffmpeg -i video_origine.avi -ab 56 -ar 44100 -b 200 -r 15 -s 320x240 -f flv video_finale.flv
Convert .avi to dv
ffmpeg -i video_origine.avi -s pal -r pal -aspect 4:3 -ar 48000 -ac 2 video_finale.dv
Or:
ffmpeg -i video_origine.avi -target pal-dv video_finale.dv
Convert .avi to mpeg for dvd players
ffmpeg -i source_video.avi -target pal-dvd -ps 2000000000 -aspect 16:9 finale_video.mpeg
Explanations :
  • target pal-dvd : Output format
  • ps 2000000000 maximum size for the output file, in bits (here, 2 Gb)
  • aspect 16:9 : Widescreen
Compress .avi to divx
ffmpeg -i video_origine.avi -s 320x240 -vcodec msmpeg4v2 video_finale.avi
Compress Ogg Theora to Mpeg dvd
ffmpeg -i film_sortie_cinelerra.ogm -s 720x576 -vcodec mpeg2video -acodec mp3 film_terminée.mpg
Compress .avi to SVCD mpeg2
NTSC format:
ffmpeg -i video_origine.avi -target ntsc-svcd video_finale.mpg
PAL format:
ffmpeg -i video_origine.avi -target pal-svcd video_finale.mpg
Compress .avi to VCD mpeg2
NTSC format:
ffmpeg -i video_origine.avi -target ntsc-vcd video_finale.mpg
PAL format:
ffmpeg -i video_origine.avi -target pal-vcd video_finale.mpg
Multi-pass encoding with ffmpeg
ffmpeg -i fichierentree -pass 2 -passlogfile ffmpeg2pass fichiersortie-2
Find a webhost with ffmpeg enabled