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25 year old Orthoptist Nickolas Colvin from Fort Severn, usually spends time with pastimes which include freshwater aquariums, Compte Brazzers gratuit and chess. Identified some amazing locales having spent 9 weeks at Surtsey.

Also visit my blog post - http://www.comptebrazzersgratuit.fr sponsor officiel

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== How can I use parameter expansion?  How can I get substrings?  How can I get a file without its extension, or get just a file's extension?  ==

Parameter expansion is a separate section of the bash manpage ({{{man bash -P 'less -p "^   Parameter Expansion"'}}} or [http://tiswww.tis.case.edu/~chet/bash/bashref.html#SEC30 see the reference]).  It can be hard to understand parameter expansion without actually using it.  (DO NOT think about parameter expansion like a regex.  It is different and distinct.)

Here's an example of how to use parameter expansion with something akin to a hostname (dot-separated components):

{{{
parameter     result
-----------   ------------------------------
${NAME}       polish.ostrich.racing.champion
${NAME#*.}           ostrich.racing.champion
${NAME##*.}                         champion
${NAME%%.*}   polish                        
${NAME%.*}    polish.ostrich.racing         
}}}

And, here's an example of the parameter expansions for a typical filename.

{{{
parameter     result
-----------   --------------------------------------------------------
${FILE}       /usr/share/java-1.4.2-sun/demo/applets/Clock/Clock.class
${FILE#*/}     usr/share/java-1.4.2-sun/demo/applets/Clock/Clock.class
${FILE##*/}                                                Clock.class
${FILE%%/*}                                                           
${FILE%/*}    /usr/share/java-1.4.2-sun/demo/applets/Clock            
}}}

You cannot nest parameter expansions.  If you need to perform two separate expansions, use a temporary variable to hold the result of the first expansion.

You may find it helpful to associate that, on your keyboard, the "#" is to the left of the "$" symbol and the "%" symbol is to its right; this corresponds with their acting upon the left (beginning) and right (end) parts of the parameter.

Here are a few more examples (but ''please'' see the real documentation for a list of all the features!).  I include these mostly so people won't break the wiki again, trying to add new questions that answer this stuff.

{{{
${string:2:1}	# The third character of string (0, 1, 2 = third)
${string:1}     # The string starting from the second character
  # Note: this is equivalent to ${string#?}
${string%?}	# The string with its last character removed.
${string: -1}	# The last character of string
${string:(-1)}	# The last character of string, alternate syntax
  # Note: string:-1 means something entirely different.

${file%.mp3}	# The filename without the .mp3 extension
  # Very useful in loops of the form: for file in *.mp3; do ...
${file%.*}	# The filename without its extension (assuming there was
  # only one extension in the first place...).
${file%%.*}	# The filename without all of its extensions
${file##*.}	# The extension only.
}}}
+year old Orthoptist Nickolas Colvin from Fort Severn, usually spends time with pastimes which include freshwater aquariums, Compte Brazzers gratuit and chess. Identified some amazing locales having spent 9 weeks at Surtsey.<<BR>><<BR>>
<<BR>><<BR>>
Also visit my blog post - [[http://www.comptebrazzersgratuit.fr|http://www.comptebrazzersgratuit.fr sponsor officiel]]