What sort of black magic I need to add to Makefile.am so that resulting Makefile could contain regular conditional make statements:
ifeq ($(SOMETHING),1)
target:
do this
else
target:
do that
endif
Please, note, that I ask exactly what I ask, no workarounds, or automake conditionals, I need that conditional in final makefile.
Let's start out with the obvious small change:
target:
ifeq ($(SOMETHING),1)
do this
else
do that
endif
If this doesn't do it, please elaborate more on why it is that you need a conditional in the final Makefile. Otherwise this feels like an XY problem.
Related
Using GNU make, I want to include a file, except if the current target is "clean".
That is, I want to do the equivalent of the following:
ifneq($(TARGET),clean)
-include somefile.txt
endif
But for that, I need a variable whose value is the target given on the command line (here named $(TARGET)). Such a variable does not seem to exist, and I can understand why, because you could have multiple targets on the command line, some of which you might want to include the file for, and others not. Actually, it would be fine if the file is included when there are other targets besides "clean". The only real problem I currently have is that when the file to be included does not exist, Make will try to build it, which is unnecessary when you're about to delete it again when executing the "clean" target.
So, is there another way to accomplish what I want?
You can use MAKECMDGOALS. Use it like this to handle multiple arguments on the command line:
ifeq (clean,$(filter clean,$(MAKECMDGOALS)))
-include somefile.txt
endif
However, this is often fraught because if you run make clean all or whatever, the include file won't be included even though it might be needed for all.
If you really need this to be reliable another way is to use recursion for your "top-level" arguments, running them one at a time in a sub-make.
You could usefully check that if clean is a target then it is the only target. Otherwise strange things can go wrong silently causing much wailing and gnashing of teeth. My most recent Makefile includes the following. (NB tested but not as yet used extensively).
ifeq (clean,$(filter clean,$(MAKECMDGOALS)))
ifneq($(strip $(filter-out clean,$(MAKECMDGOALS)))
$(error ERROR: can not make other targets with clean
endif
endif
I am trying to work through the Salt Formulas documentation and seem to be having a fundamental misunderstanding of what a salt formula really is.
Understandably, this question may seem like a duplicate of these questions, but due to my failing to grasp the basic concepts I'm also struggling to make use of the answers to these questions.
I thought, that a salt formula is basically just a package that implements extra functions, a lot like
#include <string.h>
in C, or
import numpy as np
in Python. Thus, I thought, I could download the salt-formula-linux to /srv/formulas/salt-formula-linux/, add that to file_roots, restart the master (all as per the docs), and then write a file like swapoff.sls containing
disable_swap:
linux:
storage:
swap:
file:
enabled: False
(the above is somewhat similar to the examples in the repo's root) in hope that the formula would then handle removing the swap entry from /etc/fstab and running swapoff -a for me. Needless to say, this didn't work, clearly because I'm not understanding what a salt formula is meant to be.
So, what is a salt formula and how do I use it? Can I make use of it as a library of functions too?
This answer might not be fully correct in all technicalities, but this is what solved my problem.
A salt formula is not a library of functions. It is, rather, a collection of state files. While often a state file can be very simple, such as some of my user defined
--> top.sls <--
base:
'*':
- docker
--> docker.sls <--
install_docker_1703:
pkgrepo.managed:
# stuff
pkg.installed:
- name: docker-ce
creating a state file like
--> swapoff.sls <--
disable_swap:
linux.storage.swap: # and so on
is, perhaps, not the way to go. Well, at least, maybe not for a beginner with lacking knowledge.
Instead, add an item to top.sls:
- linux.storage.swap
This is not enough, however. Most formulas (or the state files within them, if you will) are highly parametrizable, i.e. they're full of placeholders with variable names, such as {{ swap.device }}. If there's nothing to fill this gap, the state fill will not be able to do anything. These gaps are filled from pillars.
All that remains, is to create a file like swap.sls in /srv/pillar/ that would contain something like (as per the examples of that formula)
linux:
storage:
enabled: true
swap:
file:
enabled: true
engine: file
device: /swapfile
size: 1024
and also /srv/pillar/top.sls with
base:
'*':
- swap
Perhaps /srv/pillar should also be included in pillar_roots in /etc/salt/master.
So now /srv/salt/top.sls runs /srv/formulas/salt-formula-linux/linux/storage/swap.sls which using the guidance of /srv/pillar/top.sls pulls some parameters from /srv/pillar/swap.sls and enables a swapfile.
I am working on a PHP/Javascript project where I've nicely set up a build workflow. It involves testing, minifying, compressing into the final zip deliverable, and a whole lot of other nice stuff.
I want to build a task that fails when there are certain patterns in the source code. I would like to look for any print_r(), error_log(), var_dump(), etc functions, and halt the build process if there are any. Perhaps later I would like to check for things in Javascript or CSS so this is not only a PHP question.
I know it can be done with grunt-shell and grep but I'd like to know the following:
Are there any grunt plugins specific to this task? Ideally I would like to be able to specify a list of regexes per file type, and to set whether to continue or fail the build on pattern match.
How do others tackle the problem of double-checking the packaged source for the most common debug statements or other patterns?
Not a complete answer to my question, but I've recently come across this grunt plugin which is somewhat related. It removes console.log statements from JavaScript. Haven't tried it yet. Looks good. I still would like to know if there's something similar for PHP though.
http://grunt-tasks.com/grunt-remove-logging-calls/
Edit: Seeing as there's only tumbleweeds rolling in the wind here, I'm posting my workaround that's based on grunt-shell. However this is not what I was looking for. It's not perfect because it doesn't do proper syntax parsing:
shell: {
check_debug_prints: {
command: '(! (egrep -r "var_dump|print_r|error_log" --include=*.php src || egrep -r "console\.\w+|debugger;" --include=*.js src) ) || (echo "Debug prints in source - build aborted" && false )'
}
},
and
grunt.loadNpmTasks( 'grunt-shell' );
Edit 2: I finally found the exact grunt plugin I was looking for. It is grunt-search. There is a failOnMatch boolean option that lets you indicate if a particular regex pattern should cause the build to fail when found.
I have a question, I have been reviewing some code and in one script, the authors use:
if(0){
#do something
}
Any help in what if(0) means?
The author (most likely) put the block of code in an if statement so that they could easily remove it if necessary without having to comment it out (or remove it). Similar to if(true) or if(false), you just need to change one value and it would skip that code.
Upon reviewing the code, developers should remove these kinds of statements once they've finalized all their source code not to confuse others.
Looks like something that will never be executed, since 0 = FALSE. Most probably this is a manual switch to test some code in parenthesis.
How can I change the prompt of my zsh shell while still retaining the cool coloring that agnoster provides? For people who don't know, it looks like this
I want to add some things like ! and \u before the working directories. I've tried the usual PS1="! \u \w" but it just gives this:
EDIT: I found the right escaped characters for inserting information, but it cancels out the styling
How can I change the prompt while maintaining the styling?
You'd have to customise the theme, i.e. .oh-my-zsh/themes/agnoster.zsh-theme, add your own function to the build_prompt function and add whatever you need to the prompt:
## Main prompt
build_prompt() {
RETVAL=$?
prompt_status
prompt_virtualenv
prompt_context
prompt_dir
prompt_git
prompt_hg
prompt_end
}
I personally added a prompt_custom stub, which I then replace with the real prompt function in my .zshrc, so I only have to maintain that small customisation (probabaly worthty of a pull request at some stage...)
prompt_custom() {
}
You can change the prompt_context() in .oh-my-zsh/themes/.zsh-theme with the following block of code
prompt_context() {
if [[ "$USER" != "$DEFAULT_USER" || -n "$SSH_CLIENT" ]]; then
prompt_segment black default "%(!.%{%F{yellow}%}.)~"
fi
}