Showing posts from October, 2009

Common Unix - Shell Features

Overview of common shell features. 
The following features are standard in every shell. List is as follows -
Command     Meaning
>     Redirect output
>>     Append to file
<     Redirect input
<<     "Here" document (redirect input)
| Pipe     output
&     Run process in background.
;     Separate commands on same line
*     Match any character(s) in filename
?     Match single character in filename
[ ]     Match any characters enclosed
( )     Execute in subshell
` `     Substitute output of enclosed command
" "     Partial quote (allows variable and command expansion)
' '     Full quote (no expansion)
\     Quote following character
$var     Use value for variable
$$     Process id
$0     Command name
$n     nth argument (n from 0 to 9)
$*     All arguments as a simple word
#     Begin comment
bg     Background execution
break     Break from loop statements
cd     Change directories
continue     Resume a program loop
echo     Display output
eval     Evaluate ar…