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→Using Variables in Shell Scripts
'''Positional Parameters and Special Parameters'''
[[Image:positional.png|thumb|right|220px|Examples of using '''positional''' and '''special''' parameters.]]A '''positional parameter''' is a variable within a shell program; its value is set from an argument specified<br>on the command line that invokes the program.Positional parameters are numbered and are referred to<br>with a preceding "'''$'''": '''$1''', '''$2''', '''$3''', and so on. The positional parameter $0 refers to either the name of shell<br>where command was issued, or name of shell script being executed. If using '''positional parameters''' greater than '''9''', then you need to include number within braces.<br>Examples: '''echo ${10}''', '''ls ${23}'''
The '''shift''' command can be used with positional parameters to shift positional parameters<br>to the left by one or more positions.
