Wednesday, August 28, 2013

Shell Programming : 6 | special Symbols

hello.... Friends, Today we are going to discus few Basic Symbols which are vary important in the shell scripting. this is an important symbols which have some special meaning in the shell scripting.

few of them we are going to study today like :

#     $    \    "   '   `   <   >   |    ;    (    )    [    ]    ?    &   *    =    < Space >    < Tab >    <Newline >


# this symbol is used for comment or if we don't want the output in the script then we can use # symbol in our script.

$ this symbol is basically proceeds the name of a variable to be explained in the shell scripting.

\    "    '    `  these all symboles are used for quots in the script.

<  > these both symboles are used for input and output from one file to other.

| this is a pipes symbole it is used to bind two files that means output of file from left side of | will be send to as the input of the file in the right side of this symbole.

; this is the symboles which is used to seprate the multiple commands in a single line.

(  ) these symboles are  used to seprate the shells or we can say for subshells.

[  ] these symboles are used to launch the grup of commands by the shell basically the space is required after opening & closing .

& this symbole causes the preceding command to execute in the background so that next command can work without waiting.

* this command is used for matching filenames . but not from hidden files i e excepting files starting with dots in the directory.

? this symbole is used as * but just difference is to match the single charecter while * for file filename.

= when we assign the vales in a variable then we used this symbole mostly.

< Space > and < Tab > both are used to seprate the two commands.

<Newline > or \n is used to complete a command & start in the next line.


these are the few symboles which is mostly used in the shell. when we prectically design a scripts then i will try to explain them at that time.


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