-%%
-%%
-
\chapter{Variable Expansion}
\label{VarsChapter}
\index[general]{Variable Expansion }
% TODO: does the following mean that this should not be in book?
-Please note that as of version 1.37, the Variable Expansion
+Please note that as of version 1.37, the Variable Expansion
is deprecated and replaced by Python scripting (not yet
documented).
Variable expansion is somewhat similar to Unix shell variable expansion.
Currently (version 1.31), it is used only in format labels, but in the future,
-it will most likely be used in more places.
+it will most likely be used in more places.
\section{General Functionality}
\index[general]{Functionality!General }
conversion, substring selection, regular expression matching and replacement,
character class replacement, padding strings, repeated expansion in a user
controlled loop, support of arithmetic expressions in the loop start, step and
-end conditions, and recursive expansion.
+end conditions, and recursive expansion.
When using variable expansion characters in a Volume Label Format record, the
-format should always be enclosed in double quotes ({\bf "}).
+format should always be enclosed in double quotes ({\bf "}).
For example, {\bf \$\{HOME\}} will be replaced by your home directory as
defined in the environment. If you have defined the variable {\bf xxx} to be
{\bf Test}, then the reference {\bf \$\{xxx:p/7/Y/r\}} will right pad the
contents of {\bf xxx} to a length of seven characters filling with the
-character {\bf Y} giving {\bf YYYTest}.
+character {\bf Y} giving {\bf YYYTest}.
\section{Bacula Variables}
\index[general]{Bacula Variables }
\index[general]{Variables!Bacula }
Within Bacula, there are three main classes of variables with some minor
-variations within the classes. The classes are:
+variations within the classes. The classes are:
\begin{description}
\index[general]{Counters }
Counters are defined by the {\bf Counter} resources in the Director's conf
file. The counter can either be a temporary counter that lasts for the
-duration of Bacula's execution, or it can be a variable that is stored in
+duration of Bacula's execution, or it can be a variable that is stored in
the catalog, and thus retains its value from one Bacula execution to another.
Counter variables may be incremented by postfixing a plus sign ({\bf +} after
-the variable name).
+the variable name).
\item [Internal Variables]
\index[general]{Internal Variables }
Internal variables are read-only, and may be related to the current job (i.e.
Job name), or maybe special variables such as the date and time. The
-following variables are available:
+following variables are available:
\begin{itemize}
-\item [Year] -- the full year
-\item [Month] -- the current month 1-12
-\item [Day] -- the day of the month 1-31
-\item [Hour] -- the hour 0-24
-\item [Minute] -- the current minute 0-59
-\item [Second] -- the current second 0-59
-\item [WeekDay] -- the current day of the week 0-6 with 0 being Sunday
-\item [Job] -- the job name
-\item [general] -- the Director's name
-\item [Level] -- the Job Level
-\item [Type] -- the Job type
-\item [JobId] -- the JobId
-\item [JobName] -- the unique job name composed of Job and date
-\item [Storage] -- the Storage daemon's name
-\item [Client] -- the Client's name
-\item [NumVols] -- the current number of Volumes in the Pool
-\item [Pool] -- the Pool name
-\item [Catalog] -- the Catalog name
-\item [MediaType] -- the Media Type
+\item [Year] -- the full year
+\item [Month] -- the current month 1-12
+\item [Day] -- the day of the month 1-31
+\item [Hour] -- the hour 0-24
+\item [Minute] -- the current minute 0-59
+\item [Second] -- the current second 0-59
+\item [WeekDay] -- the current day of the week 0-6 with 0 being Sunday
+\item [Job] -- the job name
+\item [general] -- the Director's name
+\item [Level] -- the Job Level
+\item [Type] -- the Job type
+\item [JobId] -- the JobId
+\item [JobName] -- the unique job name composed of Job and date
+\item [Storage] -- the Storage daemon's name
+\item [Client] -- the Client's name
+\item [NumVols] -- the current number of Volumes in the Pool
+\item [Pool] -- the Pool name
+\item [Catalog] -- the Catalog name
+\item [MediaType] -- the Media Type
\end{itemize}
\item [Environment Variables]
Environment variables are read-only, and must be defined in the environment
prior to executing Bacula. Environment variables may be either scalar or an
array, where the elements of the array are referenced by subscripting the
-variable name (e.g. {\bf \$\{Months[3]\}}). Environment variable arrays are
+variable name (e.g. {\bf \$\{Months[3]\}}). Environment variable arrays are
defined by separating the elements with a vertical bar ({\bf |}), thus {\bf
set Months="Jan|Feb|Mar|Apr|..."} defines an environment variable named
{\bf Month} that will be treated as an array, and the reference {\bf
-\$\{Months[3]\}} will yield {\bf Mar}. The elements of the array can have
-differing lengths.
+\$\{Months[3]\}} will yield {\bf Mar}. The elements of the array can have
+differing lengths.
\end{description}
\section{Full Syntax}
\index[general]{Full Syntax }
Since the syntax is quite extensive, below, you will find the pseudo BNF. The
-special characters have the following meaning:
+special characters have the following meaning:
\footnotesize
-\begin{verbatim}
+\begin{lstlisting}
::= definition
( ) grouping if the parens are not quoted
| separates alternatives
* preceding item can be repeated zero or more times
? preceding item can appear zero or one time
+ preceding item must appear one or more times
-\end{verbatim}
+\end{lstlisting}
\normalsize
-And the pseudo BNF describing the syntax is:
+And the pseudo BNF describing the syntax is:
\footnotesize
-\begin{verbatim}
+\begin{lstlisting}
input ::= ( TEXT
| variable
| INDEX_OPEN input INDEX_CLOSE (loop_limits)?
INDEX_CLOSE ::= ']'
INDEX_MARK ::= '#'
NAME_CHARS ::= 'a'|...|'z'|'A'|...|'Z'|'0'|...|'9'
-\end{verbatim}
+\end{lstlisting}
\normalsize
\section{Semantics}
\index[general]{Semantics }
The items listed in {\bf command} above, which always follow a colon ({\bf :})
-have the following meanings:
+have the following meanings:
\footnotesize
-\begin{verbatim}
+\begin{lstlisting}
- perform substitution if variable is empty
+ perform substitution if variable is not empty
o cut out substring of the variable value
% special function call (none implemented)
l lower case the variable value
u upper case the variable value
-\end{verbatim}
+\end{lstlisting}
\normalsize
-The {\bf loop\_limits} are start, step, and end values.
+The {\bf loop\_limits} are start, step, and end values.
A counter variable name followed immediately by a plus ({\bf +}) will cause
-the counter to be incremented by one.
+the counter to be incremented by one.
\section{Examples}
\index[general]{Examples }
-To create an ISO date:
+To create an ISO date:
\footnotesize
-\begin{verbatim}
+\begin{lstlisting}
DLT-${Year}-${Month:p/2/0/r}-${Day:p/2/0/r}
-\end{verbatim}
+\end{lstlisting}
\normalsize
-on 20 June 2003 would give {\bf DLT-2003-06-20}
+on 20 June 2003 would give {\bf DLT-2003-06-20}
-If you set the environment variable {\bf mon} to
+If you set the environment variable {\bf mon} to
\footnotesize
-\begin{verbatim}
+\begin{lstlisting}
January|February|March|April|May|...
File-${mon[${Month}]}/${Day}/${Year}
-\end{verbatim}
+\end{lstlisting}
\normalsize
-on the first of March would give {\bf File-March/1/2003 }
+on the first of March would give {\bf File-March/1/2003 }
projects / bacula / docs / blobdiff