gmake environment variables missing - variables

I am writing a Makefile and need to access the HOSTNAME environment variable.
None of the environment variables are available. Here's the Makefile:
all:
echo $(HOSTNAME) "b"
The output is:
echo "b"
b
I am running on ubuntu 14.04 in a VM. gmake version:
make -v
GNU Make 3.81
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
This program built for x86_64-pc-linux-gnu
And yes, the HOSTNAME environment variable is set:
/tmp$ echo $HOSTNAME
ubuntu
/tmp$
This Makefile works in cygwin.
Do you know why this is not working?

HOSTNAME is set by Bash, but when Make runs a shell, it calls sh; even if this is a symlink to Bash on your system, it runs in POSIX mode, which disables many Bash-specific behaviors.
Workaround 0; always call make with Bash with HOSTNAME exported.
alias make='export HOSTNAME; make'
Workaround 1; use Bash instead of sh explicitly.
SHELL=/bin/bash
HOSTNAME=$(shell echo "$$HOSTNAME")
Workaround 2; call Bash explicitly.
HOSTNAME=$(shell bash -c 'echo $$HOSTNAME')
Workaround 3; run an external command.
HOSTNAME=$(shell uname -n)
Out of these, the last one is probably the least obscure as well as the most efficient.

Related

GNU Make Error 126, C:\Program is a directory

GNU make gives me a strange error message, which I do not understand.
gao#L8470-130213 ~
$ make
echo Test
C:\Program: C:\Program: is a directory
make: *** [test] Error 126
This is what I thought of verifying:
gao#L8470-130213 ~
$ less makefile
test:
echo Test
gao#L8470-130213 ~
$ which make
/c/Programx86/GnuWin32/bin/make
gao#L8470-130213 ~
$ /c/Progra~2/GnuWin32/bin/make.exe test
echo Test
C:\Program: C:\Program: is a directory
make: *** [test] Error 126
gao#L8470-130213 ~
$ make --version
GNU Make 3.81
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
This program built for i386-pc-mingw32
It feels like some other program is trying to run at the end, and that its path includes some spaces. In that case, what program could it be, and how can I prevent it from running?
I have seen this thread and tried to disable my antivirus, which did not help.
I have also looked into permissions, but I am not sure if makefile needs execution rights. I can't seem to be able to change that anyway (running in bash on windows. makefile is not read-only when I check in explorer):
gao#L8470-130213 ~
$ ls -l makefile
-rw-r--r-- 1 gao Administ 21 Apr 15 14:53 makefile
gao#L8470-130213 ~
$ chmod +x makefile
gao#L8470-130213 ~
$ ls -l makefile
-rw-r--r-- 1 gao Administ 21 Apr 15 14:53 makefile
What is going on with make, what can I do?
It's not "some other program" that's trying to run, it's the echo command. Make prints the command to be run, echo test, but you never see the output (test) so that means it failed trying to find the echo program. Unfortunately I'm not very familiar with the vagaries of running GNU make on Windows: there are lots of different options. One possibility would be to get a newer version of GNU make; 3.81 is very old. 3.82 is now available and might work better for you.
Good info you added above about your environment re: using bash; that wasn't clear from the original question and on Windows there are many different ways to do things. You're using the mingw version of make; that version (as I understand it) does NOT use bash as the shell to run commands in: it's supposed to be used with native Windows environments which do not, certainly, have bash available. I believe that the version of make you have is invoking commands directly, and/or using command.com. Certainly not a UNIX shell like bash.
If you want to use bash you should set the SHELL make variable to the path of your bash.exe program. If you're using a Cygwin environment you can use the GNU make that comes with Cygwin which behaves more like a traditional make + shell.
Otherwise you'll need to write your commands using Windows command.com statements.
Again, I don't use Windows so this is mostly hearsay.
PS. The makefile does not need to be executable.
What is going on is that make doesn't like file names or directory names with spaces in them, such as Program Files. Neither do most of the utilities that makefiles typically rely on, such as the shell to execute commands with.
I create a junction from Program Files to ProgramFiles and use the latter whenever I encounter cases like this.

how to set up the psql command in cygwin?

I have a local dev site on my machine with Apache server and PostgreSQL 9.1 database. As I'm using Windows, I also installed Cygwin. I want to access to database and make some queries via Cygwin insead of pgAdmin III, but it tells me that psql command not found. How should I set up the psql command in cygwin?
As of today, you just have to install postgresql-client package in cygwin:
Run your cygwin setup.exe file (this can be run multiple times to
add more packages).
Type postgresql into the search box, select postgresql-client and
press "next" to install.
Now you can open Cygwin terminal and type psql to run!
The best combo for Cygwin on Windows, I've found, is the normal Windows Postgres installation combined with Cygwin psql.
Cygwin psql (and other command-line tools) can be compiled from source fairly easily. Here's the steps for 9.2.4:
$ wget http://ftp.postgresql.org/pub/source/v9.2.4/postgresql-9.2.4.tar.bz2
$ tar xjf postgresql-9.2.4.tar.bz2
$ cd postgresql-9.2.4/
$ ./configure
$ cd src/bin/psql
$ make
This creates a psql.exe binary that works well with Cygwin. However, by default, it tries to connect to the local instance using a Unix socket instead of TCP. So use -h to specify the hostname and force TCP, for example:
$ ./psql -h localhost -U postgres
Move this psql.exe to someplace on your path (e.g. ~/bin) and possibly wrap in a script to add '-h localhost' for convenience when no other arguments supplied.
The source could be modified to change the default, but that takes actual work ;)
If I understand your question correctly you are running cygwin because you want to run queries against PostgreSQL via bash and psql on Windows, right?
Cygwin can run Windows binaries from bash, so install the native Windows builds and make sure psql.exe is in the PATH You should be able to copy the executable if necessary.
There is no need to install a native Cygwin build of PostgreSQL. Just use the existing psql tool, and make sure you can access the Windows-native psql.exe.

Custom error handling in makefile

I need to build a C program which requires a particular Linux package. I set a variable, PACKAGENOTIFICATION, to a shell command which is supposed to check if the package is installed for Ubuntu and print a notification if not:
PACKAGENOTIFICATION := if cat /etc/issue | grep Ubuntu -c >>/dev/null; then if ! dpkg -l | grep libx11-dev -c >>/dev/null; then echo "<insert notification here>"; fi; fi
[...]
maintarget: dependencies
$(PACKAGENOTIFICATION)
other_commands
Unfortunately, while making the dependencies, it runs into the files which need the package, and errors out before executing my PACKAGENOTIFICATION. An alternative formulation is to make a separate target whose only purpose is to run the notification:
maintarget: notify other_dependencies
commands
notify:
$(PACKAGENOTIFICATION)
However, since this phantom dependency always needs to be executed, make never reports that the program is up to date.
What's the best way to have make always report as up to date, but also execute my notification before it dies?
Thanks!
If your version of Make supports "order-only" prerequisites, this will do it:
# Note the pipe
maintarget: other_dependencies | notify
commands
# This should be an order-only preq of any target that needs the package
notify:
$(PACKAGENOTIFICATION)
If not, there are other approaches.

Can I use GNU make's SHELL variable to connect to a remote shell?

One of the projects I'm working on uses gnu make for testing. I would like to test on a platform that doesn't have a make implementation, but does have a POSIX shell.
Is it possible to create a script (preferably in python) that can "stitch" a remote shell to make, and put it in make's SHELL environment variable?
If not, is there another way anyone can think of to do it?
It is possible.
Create a script that forwards commands to a remote host. For example:
#!/bin/bash
shift # remove -c argument
exec ssh remote_host "$#"
And make it executable (chmod +x).
And then in Makefile:
SHELL := './my_shell.sh'
all :
#echo `hostname` is making $#
Outputs:
$ make
remote_host.peer1.net is making all

Autoconf macros for Apache and conf.d install process?

I have a package that is using the autotools to build and install.
Part of the package is a website that can be run on the local machine.
So in the package there is a .conf file that is meant to be either
copied or linked to the /etc/apache2/conf.d directory. What's the
standard way that packages would do this? If possible, I'd like for
the user not to have an extra step to make the website work. I'd like
to have them install the package and then be able to browse to
http://localhost/newpackage to get up and running.
Also, is there a way that autoconf knows about the apache install or a
standard way through then environment some how? If someone could
point me in the right direction that would be great.
Steve
The first thing you should do is to locate the apache extension tool apxs or apxs2 (depends on apache version and/or platform you are building for). After you know where your tool is located you can run queries to get certain apache config params. For example to get system config dir you can run:
apxs2 -q SYSCONFDIR
Here is a snippet of how you can locate apache extension tool: (be careful it may contain syntax errors)
dnl Note: AC_DEFUN goes here plus other stuff
AC_MSG_CHECKING(for apache APXS)
AC_ARG_WITH(apxs,
[AS_HELP_STRING([[--with-apxs[=FILE]]],
[path to the apxs, defaults to "apxs".])],
[
if test "$withval" = "yes"; then
APXS=apxs
else
APXS="$withval"
fi
])
if test -z "$APXS"; then
for i in /usr/sbin /usr/local/apache/bin /usr/bin ; do
if test -f "$i/apxs2"; then
APXS="$i/apxs2"
break
fi
if test -f "$i/apxs"; then
APXS="$i/apxs"
break
fi
done
fi
AC_SUBST(APXS)
The way to use APXS in your automake Makefile.am would look something like this:
## Find apache sys config dir
APACHE2_SYSCONFDIR = `#APXS# -q SYSCONFDIR`
## Misc automake stuff goes here
install: install-am
cp my.conf $(DESTDIR)${APACHE2_SYSCONFDIR}/conf.d/my.conf
I assume you are familiar with automake and autoconf tools.