UNIX trics

Some useful tips and tricks for UNIX.

Command Reference

The UNIX Command Reference has nearly all the frequently used UNIX commands.

Profile

If you like a prompt like:
HarmFrielink@L3AFY65 ~
$
Place this PS1 into the  .bashrc  file (UNIX Escape Sequence) Together with the folowing options:

PS1="\[\e]0;\w\a\]\n\[\e[32m\]\u@\h \[\e[33m\]\w\[\e[0m\]\n\$ "

alias dir='ls --color=auto --format=vertical'         # DOS dir
alias ll='ls -l --group-directories-first --color'    # long list
alias la='ls -Al --group-directories-first --color'   # all but . and ..
alias l='ls -CF'                                      #

If running the bashrc is not possible because the error bash: /home/chris/.bashrc: Permission denied occurs perform the following statement:
 chmod 740 ./.bashrc  or better  chmod o+rwx ./.bashrc , see below for detailed info.

An alternative PS1 prompt:

 \w:\u\$

This will produce outcome like the current directory and username:

 /Projects/xx/yy:UserName$

See for more http://bash.cyberciti.biz/guide/Changing_bash_prompt.

ls & chmod

The meaning of the different colors in  ls --color  in combination with the  drwxrwxrwx  :

File Type		Owner Access		Group Access		Other Access
- d	regular file directory	r w x	read write execute	r w x	read write execute	r w x	read write execute

The following example shows a directory for which the owner has read/write/execute access, the group has read/execute access, and all others have no access:

  drwxr-x---

File Access Descriptor
Entity		Operator		Access Rights
u g o a	user(owner) group others all of the above	+ - =	grant revoke set	r w x	read write execute

chmod examples
Command	Description
chmod u+rwx,g-rxw,o-rwx hosts	Add all rights for owner and revoke all rights for group and others on the "hosts" file.
chmod g+r hosts	Now add read access for the group.

Escape Sequence

More...

Errors

If you get the error The procedure entry point sigset could not be located in the dynamic link library cygwin1.dll install cygwin again.

UNIX Tutorials

• BASH Scripting Guide for beginners
• UNIX tutorial, a good start

See also

• Unix
• Cygwin