Here are some shell special variables:
Special Shell Variables:
VariableMeaning
$0Filename of script
$1Positional parameter #1
$2 - $9Positional parameters #2 - #9
${10}Positional parameter #10
$#Number of positional parameters
"$*"All the positional parameters (as a single word) *
"$@"All the positional parameters (as separate strings)
${#*}Number of positional parameters
${#@}Number of...
Educating yourself does not mean that you were stupid in the first place; it means that you are intelligent enough to know that there is plenty left to 'learn'. -Melanie Joy
Monday, 1 April 2013
Parameters/String Operations on shell (Bash) without using any third party tools
Parameter Substitution and Expansion:
ExpressionMeaning
${var}Value of var (same as $var)
${var-DEFAULT}If var not set, evaluate expression as $DEFAULT *
${var:-DEFAULT}If var not set or is empty, evaluate expression as $DEFAULT *
${var=DEFAULT}If var not set, evaluate expression as $DEFAULT * (value is assigned to var)
${var:=DEFAULT}If var not...