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Full Discussion: How to use $variable in conditional sentences?
Top Forums Shell Programming and Scripting How to use $variable in conditional sentences? Post 302997607 by bakunin on Wednesday 17th of May 2017 08:41:52 AM
Old 05-17-2017
I think you mix up two different things: shell scripts and makefiles.

Makefiles (more precisely: the make-utility) work rule-based, so you don't need explicit conditionals - everything is a conditional anyway.

make works like that: you define so-called "dependencies" between files: i.e. you have three object files where each depends on a single source file. Whenever one of the source file changes the corresponding object file has to be generated anew. This is done by executing the code in the rule-definition. For every dependency you can create a rule, but usually you create rules for groups of dependencies: whenever ".c" (the source) changes, the corresponding ".obj" (the object) has to be generated and the rule for this is to call the compiler to compile exactly the one source-file. For this there are "make-variables" like "$@", "$<", etc., which are filled with the name(s) of the files involved in the rule. See the man-page of make for details.

You can also create cascades of these rules: you base .obj-files on .c-files and you base executables on the .obj-files. So, when a source file changes, the corresponding object is generated and in turn this leads to the executable being generated too (by calling the linker to link all the objects to the executable.

You might want to read this little introduction i once wrote.

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
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LEARN ABOUT SUSE

dadadodo

dadadodo(1)                                                   General Commands Manual                                                  dadadodo(1)

NAME

       dadadodo - exterminate all rational thought

SYNOPSIS

       dadadodo [ options ] [ input-files ]

DESCRIPTION

       dadadodo is a program that analyses texts for Markov chains of word probabilities and then generates random sentences based on those proba-
       bilities.  Sometimes these sentences are nonsense, but sometimes they cut right through to the heart of the matter and reveal hidden  mean-
       ings.

OPTIONS

       dadadodo accepts the following options:

       -c, -count n
              Generate n sentences.

       -h, -help
              Show summary of options and exit.

       -html  Output HTML instead of plain text.

       -l, -load file
              Load compiled data from file ('-' for standard input).

       -o, -output file
              Save compiled data in file ('-' for standard output).

       -p, -pause s
              Delay s seconds between paragraphs.

       -w, -columns columns
              Format  output  for  a  device columns character cells in width.  If not specified, the value of the environment variable COLUMNS is
              used to determine the width.  If that variable is not defined, a width of 72 is assumed.

NOTES

       Non-option arguments are input files.  These should be text files, but may be mail folders or HTML.  MIME messages  are  handled  sensibly.
       When  no  output  file is specified, sentences will be generated from the input data directly.  However, loading a saved file is far faster
       than re-parsing the text files each time.

ENVIRONMENT

       COLUMNS
              Determines the width (in character cells) of the output if the -w, -columns option is not used.  If  not  set,  a  width  of  72  is
              assumed.

SEE ALSO

       dadadodo's upstream website is http://www.jwz.org/dadadodo/.

AUTHOR

       dadadodo was written by Jamie Zawinski.

       This manual page was written by Sudhakar Chandrasekharan <thaths@netscape.com>, based on the program's usage message.

                                                                                                                                       dadadodo(1)
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