As noted in other answers, make(1) has a `-C`  option for this; several commands have similar options (e.g. tar).  It is useful to note that for other commands which lack such options the following can be used:

    (cd /dir/path &amp;&amp; command-to-run)

This runs the command in a sub-shell which first has its working directory changed (while leaving the working directory of the parent shell alone).  Here `&amp;&amp;`  is used instead of `;`  to catch error cases where the directory can not be changed.

If the reason you don&#39;t want to cd to a directory is because you need to stay in the current directory for a later task, you can use pushd and popd:

    pushd ProjectDir ; make ; popd

That goes into the ProjectDir, runs make, and goes back to where you were.

Also you may use:

    make --directory /path/to/dir

makefile:

    all:
        gcc -Wall -Wpedantic -std=gnu99 -g src/test.c -o build/test

    run:
        ./build/test
or

    run:
        ./../build/test

etc.

Is there a character in JavaScript to break up a line of code so that it is read as continuous despite being on a new line?

Something like....

&lt;pre&gt;
1. alert ( &quot;Please Select file   
2. \ to delete&quot; );
&lt;/pre&gt;


How do I break a string across more than one line of code in JavaScript?

Seemingly simple, but I cannot find anything relevant on the web.

What is the correct HTML code for an apostrophe? Is it `&amp;#8217;`?

HTML code for an apostrophe

In Unix, can I run `make` in a directory without `cd`&#39;ing to that directory first?

In Unix, can I run &#39;make&#39; in a directory without cd&#39;ing to that directory first?

<p>In Unix, can I run <code>make</code> in a directory without <code>cd</code>'ing to that directory first?</p>


The idle task (a.k.a. swapper task) is chosen to run when no more runnable tasks in the run queue at the point of task scheduling. But what is the usage for this so special task? Another question is why i can&#39;t find this thread/process in the &quot;ps aux&quot; output (PID=0) from the userland?

Why do we need a swapper task in linux?

I am looking for a Linux command-line tool that would report the disk IO activity. Something similar to `htop` would be really cool.  Has someone heard of something like that?

an htop-like tool to display disk activity in linux

I&#39;m trying to search and replace a string in all files matched by grep:

`grep -n &#39;foo&#39; *` will give me output in the form:

    [filename]:[line number]:[text]

For each file returned by grep, I&#39;d like to modify the file by replacing `foo` with `bar`.

Command line: search and replace in all filenames matched by grep

I searched my Linux box and saw this typedef:

    typedef __time_t time_t;

But I could not find the `__time_t`  definition.

What is time_t ultimately a typedef to?

Under Linux, how do I find out which process is using the swap space more?

How to find out which processes are using swap space in Linux?

Consider a **Save As** dialog with a free text entry where the user enters a file name as free text, then clicks a **Save** button.  The software then validates the file name, and saves the file if the name is valid.

On a Unix file system, what rules should be applied in the validation such that:

 - The name will not be difficult to manipulate later in terms of escaping special characters, etc.
 - The rules are not so restrictive that saving a file becomes non-user-friendly.

So basically, what is the *minimum* set of characters that should be restricted from a Unix file name?



What characters should be restricted from a Unix file name?

It is quite simple to run a Unix command from Java. 

    Runtime.getRuntime().exec(myCommand);

But is it possible to run a Unix shell script from Java code? If yes, would it be a good practice to run a shell script from within Java code?

How to run Unix shell script from Java code?

I&#39;d like a daemonizer that can turn an arbitrary, generic script or command into a &lt;a href=&quot;http://en.wikipedia.org/wiki/Daemon_(computer_software)&quot;&gt;daemon&lt;/a&gt;.

There are two common cases I&#39;d like to deal with:

 1. I have a script that should run forever.  If it ever dies (or on reboot), restart it.  Don&#39;t let there ever be two copies running at once (detect if a copy is already running and don&#39;t launch it in that case).

 2. I have a simple script or command line command that I&#39;d like to keep executing repeatedly forever (with a short pause between runs).  Again, don&#39;t allow two copies of the script to ever be running at once.

Of course it&#39;s trivial to write a &quot;while(true)&quot; loop around the script in case 2 and then apply a solution for case 1, but a more general solution will just solve case 2 directly since that applies to the script in case 1 as well (you may just want a shorter or no pause if the script is not intended to ever die (of course if the script really *does* never die then the pause doesn&#39;t actually matter)).

Note that the solution should not involve, say, adding file-locking code or PID recording to the existing scripts.

More specifically, I&#39;d like a program &quot;daemonize&quot; that I can run like

    % daemonize myscript arg1 arg2

or, for example, 

    % daemonize &#39;echo `date` &gt;&gt; /tmp/times.txt&#39;

which would keep a growing list of dates appended to times.txt. (Note that if the argument(s) to daemonize is a script that runs forever as in case 1 above, then daemonize will still do the right thing, restarting it when necessary.)  I could then put a command like above in my .login and/or cron it hourly or minutely (depending on how worried I was about it dying unexpectedly).

NB: The daemonize script will need to remember the command string it is daemonizing so that if the same command string is daemonized again it does not launch a second copy.

Also, the solution should ideally work on both OS X and linux but solutions for one or the other are welcome.

EDIT: It&#39;s fine if you have to invoke it with `sudo daemonize myscript myargs`.

(If I&#39;m thinking of this all wrong or there are quick-and-dirty partial solutions, I&#39;d love to hear that too.)

&lt;hr&gt;

PS: In case it&#39;s useful, [here&#39;s](https://stackoverflow.com/questions/473620/how-do-you-create-a-daemon-in-python) a similar question specific to python.



And [this](https://stackoverflow.com/questions/38596/whats-the-best-way-to-keep-a-php-script-running-as-a-daemon/39609#39609) answer to a similar question has what appears to be a useful idiom for a quick-and-dirty demonizing of an arbitrary script:



How do I daemonize an arbitrary script in unix?

So, if I&#39;m in my home directory and I want to move foo.c to ~/bar/baz/foo.c , but those directories don&#39;t exist, is there some way to have those directories automatically created, so that you would only have to type

    mv foo.c ~/bar/baz/ 

and everything would work out? It seems like you could alias mv to a simple bash script that would check if those directories existed and if not would call mkdir and then mv, but I thought I&#39;d check to see if anyone had a better idea.

Is there a way to make mv create the directory to be moved to if it doesn&#39;t exist?

    $ time foo
    real        0m0.003s
    user        0m0.000s
    sys         0m0.004s
    $

What do `real`, `user` and `sys` mean in the output of time?

Which one is meaningful when benchmarking my app?

What do &#39;real&#39;, &#39;user&#39; and &#39;sys&#39; mean in the output of time(1)?

What&#39;s the difference between CPPFLAGS and CXXFLAGS in GNU Make?

Difference between CPPFLAGS and CXXFLAGS in GNU Make

I am writing a Makefile with a lot of repetitive stuff, e.g.

    debug_ifort_Linux:
            if [ $(UNAME) = Linux ]; then                           \
              $(MAKE) FC=ifort FFLAGS=$(difort) PETSC_FFLAGS=&quot;...&quot;  \
                      TARGET=$@ LEXT=&quot;ifort_$(UNAME)&quot; -e syst;      \
            else                                                    \
              echo $(err_arch);                                     \
              exit 1;                                               \
            fi

where the target &#39;syst&#39; is defined, the variable &#39;UNAME&#39; is defined (and is usually Linux, but might also by Cygwin or OSF1) and the variables &#39;difort&#39; and &#39;err_arch&#39; are also defined. This block of code is used very many times for different compiler targets (using a name convention of &#39;&lt;debug|profile|optim&gt;_&lt;compiler&gt;_&lt;uname&gt;&#39;). Since this is a huge amount of redundant code, I would like to be able to write it in a more simple manner. E.g., I would like to do something like this:

    debug_ifort_Linux:
            compile(uname,compiler,flags,petsc_flags,target,lext)

where compile could be a function doing the code above based on the arguments. Does anyone have any idea how I could accomplish this?

Functions in Makefile

What is the usage of the -I and -L flags in a makefile?


What is the difference between -I and -L in makefile?

A few years ago, I read the [Recursive Make Considered Harmful](http://aegis.sourceforge.net/auug97.pdf) paper and implemented the idea in my own build process.  Recently, I read another article with ideas about how to [implement non-recursive `make`](http://sites.e-advies.nl/nonrecursive-make.html).  So I have a few data points that non-recursive `make` works for at least a few projects.

But I&#39;m curious about the experiences of others.  Have you tried non-recursive `make`?  Did it make things better or worse?  Was it worth the time?

What is your experience with non-recursive make?

I often find [Bash][1] syntax very helpful, e.g. process substitution like in `diff &lt;(sort file1) &lt;(sort file2)`.

Is it possible to use such Bash commands in a Makefile? I&#39;m thinking of something like this:

    file-differences:
        diff &lt;(sort file1) &lt;(sort file2) &gt; $@

In my GNU Make 3.80 this will give an error since it uses the `shell` instead of `bash` to execute the commands.

  [1]: http://en.wikipedia.org/wiki/Bash_%28Unix_shell%29


Content Type	Original Author	Original Content on Stackoverflow
Question	user46795	View Question on Stackoverflow
Solution 1 - Linux	bmotmans	View Answer on Stackoverflow
Solution 2 - Linux	Dave C	View Answer on Stackoverflow
Solution 3 - Linux	EnigmaCurry	View Answer on Stackoverflow
Solution 4 - Linux	korst1k	View Answer on Stackoverflow
Solution 5 - Linux	oldpilsbury	View Answer on Stackoverflow

In Unix, can I run 'make' in a directory without cd'ing to that directory first?

Linux Problem Overview

Linux Solutions

Solution 1 - Linux

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HTML code for an apostrophe

How do I break a string across more than one line of code in JavaScript?

Attributions