Login or Register to Ask a Question and Join Our Community

Sponsored Content
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:
icvallejo
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

spliting up sentences

hello, i'm looking to split up text into a list of words but can't figure it out, any help would be great. thanks steven (2 Replies)
Discussion started by: stevox
2 Replies

2. Shell Programming and Scripting

How to identify sentences from a text?

Hi, I have to identify sentences from this text. If i split these statements by this way: @sentence= split(/\.\W*/,$text); I will get these following things also in the output along with proper sentences. Biol Reprod. 2002 Mar;66(3):785-95. Egydio de Carvalho C, Tanaka H,... (2 Replies)
Discussion started by: vanitham
2 Replies

3. Shell Programming and Scripting

comparing sentences

Hi, I have a file and that file contains the following sentences. Here we show that a virus-encoded transcription factor, viral mRNA, cellular RNA-binding protein heterodimer G3BP/Caprin-1 (p137), translation initiation factors eIF4E and eIF4G, and ribosomal proteins are concentrated in the... (4 Replies)
Discussion started by: vanitham
4 Replies

4. UNIX for Dummies Questions & Answers

How to filter sentences??

Hi, I have few sentences here. $a1="Division of Hematology-Oncology, and Stem cell transplantation, Schneider Childrens Hospital, Albert Einstein College of Medicine, New Hyde Park, New York. "; $a2="Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung... (3 Replies)
Discussion started by: vanitham
3 Replies

5. Programming

Conditional Compilation based on Environmental Variable in Unix

I want to be able to access an environment variable to control how a program is compiled. So: export MY_VERSN=9 Then ideally, within my C++ code, I would have #if MY_VERSN = 9 iret = FRED9() #else iret = FRED() #endif The way I thought I could do it is that in the script that... (2 Replies)
Discussion started by: BrighterLater
2 Replies

6. Shell Programming and Scripting

set variable using 'ls' with an 'or' conditional statement

Hi, I would like to set a variable using ls, but I need to be able to list two possibilities simultaneously, i.e., I'd like to do this all on one line. These are the two possible directories, but keep in mind only *one* will be present at any given time: drwxrwxrwx 4 qtv qtv 16384 Nov 9... (5 Replies)
Discussion started by: goodbenito
5 Replies

7. Shell Programming and Scripting

awk conditional expression to compare field number and variable value

Hi, I'm trying to compare the value in a field to the value in a variable using awk. This works: awk '$7 == "101"'but this is what I want (and it doesn't work): value=101 awk '$7 == "$value"' Any help or insight on this would be great. Thanks in advance. (1 Reply)
Discussion started by: goodbenito
1 Replies

8. UNIX for Dummies Questions & Answers

extracting sentences that only contain a word

Hi guys Need your help how do I extract sentences with only a word i.e. today is hot hot very humid humid2 Sample output hot very (0 Replies)
Discussion started by: jamestan
0 Replies

9. Shell Programming and Scripting

extracting sentences that only contain a word

Hi guys Need your help how do I extract sentences with only a word i.e. today is hot hot very humid humid2 Sample output hot (6 Replies)
Discussion started by: jamestan
6 Replies

10. Shell Programming and Scripting

Using awk to find sentences.

I am trying to print out sentences that meets a regular expression in awk (I’m open to using other tools, too). I got the regular expression I want to use, "(\+ \{4\})" from user ripat in a grep forum. Unfortunately with grep I couldn't print only the sentence. While searching for awk... (8 Replies)
Discussion started by: danbroz
8 Replies

LEARN ABOUT DEBIAN

jocamldep

JOCAMLDEP(1)						      General Commands Manual						      JOCAMLDEP(1)

NAME

       jocamldep - Dependency generator for JoCaml

SYNOPSIS

       jocamldep [ -I lib-dir ] filename ...

DESCRIPTION

       The  jocamldep(1) command scans a set of Objective Caml source files (.ml and .mli files) for references to external compilation units, and
       outputs dependency lines in a format suitable for the make(1) utility. This ensures that make will compile the source files in the  correct
       order, and recompile those files that need to when a source file is modified.

       The typical usage is:

       jocamldep options *.mli *.ml > .depend

       where .depend is the file that should contain the dependencies.

       Dependencies are generated both for compiling with the bytecode compiler jocamlc(1) and with the native-code compiler jocamlopt(1).

OPTIONS

       The following command-line option is recognized by jocamldep(1).

       -I directory
	      Add  the given directory to the list of directories searched for source files. If a source file foo.ml mentions an external compila-
	      tion unit Bar, a dependency on that unit's interface bar.cmi is generated only if the source for bar is found in the current  direc-
	      tory  or	in  one  of the directories specified with -I.	Otherwise, Bar is assumed to be a module form the standard library, and no
	      dependencies are generated. For programs that span multiple directories, it is recommended to pass jocamldep(1) the same -I  options
	      that are passed to the compiler.

       -native
	      Generate	dependencies for a pure native-code program (no bytecode version).  When an implementation file (.ml file) has no explicit
	      interface file (.mli file), jocamldep(1) generates dependencies on the bytecode compiled	file  (.cmo  file)  to	reflect  interface
	      changes.	 This  can cause unnecessary bytecode recompilations for programs that are compiled to native-code only.  The flag -native
	      causes dependencies on native compiled files (.cmx) to be generated instead of on .cmo files.  (This flag makes no difference if all
	      source files have explicit .mli interface files.)

SEE ALSO

       jocamlc(1), jocamlopt(1).
       The Objective Caml user's manual, chapter "Dependency generator".

																      JOCAMLDEP(1)
All times are GMT -4. The time now is 03:47 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy