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Abort makefile if variable not set
... an auxiliary function for that:
# Check that given variables are set and all have non-empty values,
# die with an error otherwise.
#
# Params:
# 1. Variable name(s) to test.
# 2. (optional) Error message to print.
check_defined = \
$(strip $(foreach 1,$1, \
$(call __check_defined,$...
Rails 4 multiple image or file upload using carrierwave
...tiple_image_upload_carrierwave
In gem file
gem 'carrierwave'
bundle install
rails generate uploader Avatar
Create post scaffold
rails generate scaffold post title:string
Create post_attachment scaffold
rails generate scaffold post_attachment post_id:integer avatar:string
rake db:migrate
...
How to list all tags along with the full message in git?
I want git to list all tags along with the full annotation or commit message. Something like this is close:
8 Answers
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Ruby replace string with captured regex pattern
...d answer first without reading the entirety of answers. That seems to generally be the most efficient means of fixing a problem. Give Vicky a break! :)
– Josh M.
Jan 31 '14 at 3:43
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Why #define TRUE (1==1) in a C boolean macro instead of simply as 1?
...type (and resolve to true and false) if the compiler supports it. (specifically, C++)
However, it would be better to check whether C++ is in use (via the __cplusplus macro) and actually use true and false.
In a C compiler, this is equivalent to 0 and 1.
(note that removing the parentheses will bre...
How to set Java environment path in Ubuntu
I just installed JDK in Ubuntu with sudo apt-get install openjdk-6-jdk command,
after the installation where's the Java bin directory located? And how can I set the environment path for that directory? I have little experience with Ubuntu, can anyone give some advice or suggest any good website ...
Which characters need to be escaped when using Bash?
...h but also bash.
1. Put the whole string in single quotes
This works for all chars except single quote itself. To escape the single quote, close the quoting before it, insert the single quote, and re-open the quoting.
'I'\''m a s@fe $tring which ends in newline
'
sed command: sed -e "s/'/'\\\\'...
Troubleshooting “Illegal mix of collations” error in mysql
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This is generally caused by comparing two strings of incompatible collation or by attempting to select data of different collation into a combined column.
The clause COLLATE allows you to specify the collation used in the query.
For exa...
Extracting text OpenCV
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For some cards the bounding box does not enclose all of the text, such as half a letter getting cut off. Such as this card: i.imgur.com/tX3XrwH.jpg How can I extend every bounding bounding boxes height and width by n? Thanks for the solution it works great!
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Where are $_SESSION variables stored?
...ariable storage is determined by PHP's session.save_path configuration. Usually this is /tmp on a Linux/Unix system. Use the phpinfo() function to view your particular settings if not 100% sure by creating a file with this content in the DocumentRoot of your domain:
<?php
phpinfo();
?>
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