From 9d0f731ad5c6e3e9ccda43651eb4f445fc8234f0 Mon Sep 17 00:00:00 2001 From: alexandre medeiros Date: Sun, 22 Sep 2013 01:29:05 -0300 Subject: Improve bash variable info --- bash.html.markdown | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/bash.html.markdown b/bash.html.markdown index 41d0669e..81565b6d 100644 --- a/bash.html.markdown +++ b/bash.html.markdown @@ -36,8 +36,22 @@ VARIABLE = "Some string" # Using the variable: echo $VARIABLE echo "$VARIABLE" +echo '$VARIABLE' # When you use the variable itself — assign it, export it, or else — you write # its name without $. If you want to use variable's value, you should use $. +# Note that ' (single quote) won't expand the variables! + +# String substitution in variables +echo ${VARIABLE/Some/A} +# This will substitute the first occurance of "Some" with "A" + +# Bultin variables: +# There are some useful builtin variables, like +echo "Last program return value: $?" +echo "Script's PID: $$" +echo "Number of arguments: $#" +echo "Scripts arguments: $@" +echo "Scripts arguments separeted in different variables: $1 $2..." # Reading a value from input: echo "What's your name?" -- cgit v1.2.3