2006/08/24
Dx is developed to be used as a SSI(server side include), however it is designed as a tool to process documents not only of HTML format but also of a generic type of documents.
Dx processes the documents to replace environment variables with its value and commands with its output as well as NCSA SSI does. However the syntax is much simpler and more powerful than NCSA SSI.
Note: the version is 0.5. This means current version is merely a trial one.
Note: use rit instead. rit is more poweful than dx, more flexible, and easier to learn.
dx [-s][-e] [file [arg ...]]The result is written to stdout.
Dx processes stdin unless file is specified. If file is specified, dx has two options:-s: skip the first line in the file.-e: stop to process on error.$variable${commandline}$[condition]{commandline}variable denotes an environment variable, commandline denotes command line and condition denotes a condition to execute a command$ is effective only if it is followed by variable name or { or [.] and { result in error.{commandline} is allowed to be written in more than one line, however [condition] must be written in one line.
Double doller $$ is converted to single $.
And single doller $ at the end of line restrains new line.
Dx replaces $variable with its value if the value exist. If not, $variable is replaced by null string.
$0, $1, $2, ... $0 is executable file that invoked <code>dx<code> $1 the first argument of the file $2 the second argument of the file $3 ...Environment variables are not array like that of
rc. (This should be improved in future.) therefore if we execute ${cmd='ls -l' $cmd}
dx will say there is no 'ls -l'.