diff options
Diffstat (limited to 'bash.html.markdown')
| -rw-r--r-- | bash.html.markdown | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/bash.html.markdown b/bash.html.markdown index a6bd2b7c..d5d08e9d 100644 --- a/bash.html.markdown +++ b/bash.html.markdown @@ -15,7 +15,7 @@ Nearly all examples below can be a part of a shell script or executed directly i [Read more here.](http://www.gnu.org/software/bash/manual/bashref.html) ```bash -#!/bin/sh +#!/bin/bash # First line of the script is shebang which tells the system how to execute # the script: http://en.wikipedia.org/wiki/Shebang_(Unix) # As you already figured, comments start with #. Shebang is also a comment. @@ -46,11 +46,15 @@ echo '$VARIABLE' echo ${VARIABLE/Some/A} # This will substitute the first occurance of "Some" with "A" +# Substring from a variable +echo ${VARIABLE:0:7} +# This will return only the first 7 characters of the value + # Default value for variable echo ${FOO:-"DefaultValueIfFOOIsMissingOrEmpty"} # This works for null (FOO=), empty string (FOO=""), zero (FOO=0) returns 0 -# Bultin variables: +# Builtin variables: # There are some useful builtin variables, like echo "Last program return value: $?" echo "Script's PID: $$" |