Misc skills
export command search path
export javadir=/data/workspace/java/ export PATH=$PATH:/home/yezheng/personal/ export PATH=$PATH:/data/workspace/java/lucene2.4/bin/ export PATH=$PATH:/data/soft/google/google_appengine/ export PATH=$PATH:/data/soft/wine/winelocale-read-only/current
Prompt Display
To let bash return "user@hostname:path/to/directory$" as your prompt, add the following line to your ~/.bash_profile:
export PS1='\u@\H:\w$'
to make the changes take effect immediately, run the following command in every open window (or restart Terminal):
source ~/.bash_profile
Inside PS1 value, "\w" represents the full path, where "\W" represents the current directory name only.
Display Disk Speed Info
sudo hdparm -tT /dev/hda
Bash Rename File Extensions
Below is a simple example for renaming uppercase jpg files to lowercase:
for i in *.JPG; do mv $i ${i%%.JPG}.jpg; done
If you would like to use this function for other types of files here is a basic template:
for i in *.; do mv $i ${i%%. }. ; done
Another example
for i in *.JPG; do j=`echo $i | cut -d . -f 1`; j=$j"_from_mark.jpg"; echo $j; mv $i $j; done;
Display Ubuntu version
lsb_release -a OR cat /proc/version
APT install
- dropbox
sudo add-apt-repository ppa:hertzog/nautilus-dropbox sudo apt-get update sudo apt-get install nautilus-dropbox
- java
sudo apt-get install python-software-properties sudo add-apt-repository ppa:ferramroberto/java sudo apt-get update sudo apt-get install sun-java6-jdk sun-java6-plugin sudo update-alternatives --config java
evince: Chinese support
just install xpdf
Count the number files in a tar
tar -tf trec_data1.tar | wc -lTask: List the contents of a tar file
Use the following command:
$ tar -tvf file.tar
Task: List the contents of a tar.gz file
Use the following command:
$ tar -ztvf file.tar.gz
Task: List the contents of a tar.bz2 file
Use the following command:
$ tar -jtvf file.tar.bz2
Where,
- t: List the contents of an archive
- v: Verbosely list files processed (display detailed information)
- z: Filter the archive through gzip so that we can open compressed (decompress) .gz tar file
- j: Filter archive through bzip2, use to decompress .bz2 files.
- f filename: Use archive file called filename
Extract images from a PDF document
pdfimages -j foo.pdf bar