Operating Systems – Page 2

alex-arriaga April 10, 2015

Solving Drupal error: PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away

Databases, Drupal, GNU/Linux, Mac OSX, MySQL, Operating Systems, PHP, Web Development, Windows No Reply

The problem

After downloading a Drupal project I am working on, and importing its database I got this kind of message related with a PDO Exception:

Additional uncaught exception thrown while handling exception.

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT s.lid, t.translation, s.version FROM {locales_source} s LEFT JOIN {locales_target} t ON s.lid = t.lid AND t.language = :language WHERE s.source = :source AND s.context = :context AND s.textgroup = 'default'; Array ( [:language] => es [:source] => Configure how content input by users is filtered, including allowed HTML tags. Also allows enabling of module-provided filters. [:context] => ) in locale() (line 720 of /Applications/AMPPS/www/sites/drupal/modules/locale/locale.module).

Solution

This is an issue related with the MySQL configuration, for solving it,

1) Go to your MySQL configuration file: my.cnf. In my case that file is in /Applications/AMPPS/conf (I use AMPPS on OS X Yosemite).

2) Look for max_allowed_packet parameter and increase it as in this example (you will usually find this parameter twice in my.cnf file).

// My default value
max_allowed_packet = 1M

// The new value
max_allowed_packet = 256M

// My default value

max_allowed_packet = 1M

// The new value

max_allowed_packet = 256M

3) Restart your MySQL server.

I hope you find this post useful, see you next time!

alex-arriaga April 10, 2015

SOLVED: Git remote ref does not exist when trying to delete branches

Git, GNU/Linux, Mac OSX, Operating Systems, Web Development, Windows 1 Reply

The problem

Today, I was updating an old git repository but when I tried to delete some branches in my local environment and in the remote, I received this kind

“remote ref does not exist”

And that is because some remote branches didn’t exist anymore.

Solution

In order to update the references in our local machine we can use the git fetch command in this format:

git fetch -p MY_REMOTE

// Example
git fetch -p origin

git fetch -p MY_REMOTE

// Example

git fetch -p origin

From Stack Overflow:

“The -p option tells fetch to delete any tracking branches that no longer exist in the corresponding remotes; by default they are kept around”.

That’s it for today enjoy your work!

alex-arriaga October 2, 2014

How to get metadata of images in Mac OSX

Mac OSX, Operating Systems No Reply

Today, one of our clients was having an issue with images on iOS devices, so, the first thing they asked us, was about if the images were in the right format, for answering that, we had to obtain the metadata of every single image and see if the extension matched with the real information. So, let me show you two options for getting this information, probably some day you will find them useful:

An great tool

I really recommend ExifTool because give us interesting information about the images, and also can write this metadata.

ExifTool is a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in a wide variety of files.

Taken from: http://www.sno.phy.queensu.ca/~phil/exiftool/

1) Get a copy (tar.gz) of the command line version: http://www.sno.phy.queensu.ca/~phil/exiftool/

2) Run following command:

./exiftool /path/to/your/image/image_name.png

1	./exiftool /path/to/your/image/image_name.png

For example:

./exiftool ../alex-arriaga.png

1	./exiftool ../alex-arriaga.png

Example of output:

ExifTool Version Number         : 9.72
File Name                       : alex-arriaga.png
Directory                       : ..
File Size                       : 8.1 kB
File Modification Date/Time     : 2014:10:02 14:37:07-05:00
File Access Date/Time           : 2014:10:02 14:41:21-05:00
File Inode Change Date/Time     : 2014:10:02 14:37:09-05:00
File Permissions                : rw-r-----
File Type                       : JPEG
MIME Type                       : image/jpeg
JFIF Version                    : 1.01
Resolution Unit                 : inches
X Resolution                    : 72
Y Resolution                    : 72
Image Width                     : 200
Image Height                    : 180
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:4:4 (1 1)
Image Size                      : 200x180

ExifTool Version Number : 9.72

File Name : alex-arriaga.png

Directory : ..

File Size : 8.1 kB

File Modification Date/Time : 2014:10:02 14:37:07-05:00

File Access Date/Time : 2014:10:02 14:41:21-05:00

File Inode Change Date/Time : 2014:10:02 14:37:09-05:00

File Permissions : rw-r-----

File Type : JPEG

MIME Type : image/jpeg

JFIF Version : 1.01

Resolution Unit : inches

X Resolution : 72

Y Resolution : 72

Image Width : 200

Image Height : 180

Encoding Process : Baseline DCT, Huffman coding

Bits Per Sample : 8

Color Components : 3

Y Cb Cr Sub Sampling : YCbCr4:4:4 (1 1)

Image Size : 200x180

The interesting part of this output is even if I change the extension, the metadata says “Hey! You are a JPEG image, but your name is with PNG extension”.

Another option (bad option)

We also have mdls but the disadvantage of this tool is that if we change the extension, the tool will give us wrong information, let’s see an example:

mdls alex-arriaga.png

1	mdls alex-arriaga.png

Example of result (wrong):

kMDItemBitsPerSample           = 32
kMDItemColorSpace              = "RGB"
kMDItemContentCreationDate     = 2014-10-02 19:37:07 +0000
kMDItemContentModificationDate = 2014-10-02 19:37:07 +0000
kMDItemContentType             = "public.png"
kMDItemContentTypeTree         = (
    "public.png",
    "public.image",
    "public.data",
    "public.item",
    "public.content"
)
kMDItemDateAdded               = 2014-10-02 19:38:37 +0000
kMDItemDisplayName             = "alex-arriaga.png"
kMDItemFSContentChangeDate     = 2014-10-02 19:37:07 +0000
kMDItemFSCreationDate          = 2014-10-02 19:37:07 +0000
kMDItemFSCreatorCode           = ""
kMDItemFSFinderFlags           = 0
kMDItemFSHasCustomIcon         = (null)
kMDItemFSInvisible             = 0
kMDItemFSIsExtensionHidden     = 0
kMDItemFSIsStationery          = (null)
kMDItemFSLabel                 = 0
kMDItemFSName                  = "alex-arriaga.png"
kMDItemFSNodeCount             = (null)
kMDItemFSOwnerGroupID          = 20
kMDItemFSOwnerUserID           = 501
kMDItemFSSize                  = 8305
kMDItemFSTypeCode              = ""
kMDItemHasAlphaChannel         = 0
kMDItemKind                    = "Portable Network Graphics image"
kMDItemLogicalSize             = 8305
kMDItemOrientation             = 0
kMDItemPhysicalSize            = 12288
kMDItemPixelCount              = 36000
kMDItemPixelHeight             = 180
kMDItemPixelWidth              = 200
kMDItemResolutionHeightDPI     = 72
kMDItemResolutionWidthDPI      = 72
kMDItemWhereFroms              = (
    "http://www.alex-arriaga.com/wp-content/themes/fenix/img/alex-arriaga.jpg",
    ""
)

kMDItemBitsPerSample = 32

kMDItemColorSpace = "RGB"

kMDItemContentCreationDate = 2014-10-02 19:37:07 +0000

kMDItemContentModificationDate = 2014-10-02 19:37:07 +0000

kMDItemContentType = "public.png"

kMDItemContentTypeTree = (

"public.png",

"public.image",

"public.data",

"public.item",

"public.content"

)

kMDItemDateAdded = 2014-10-02 19:38:37 +0000

kMDItemDisplayName = "alex-arriaga.png"

kMDItemFSContentChangeDate = 2014-10-02 19:37:07 +0000

kMDItemFSCreationDate = 2014-10-02 19:37:07 +0000

kMDItemFSCreatorCode = ""

kMDItemFSFinderFlags = 0

kMDItemFSHasCustomIcon = (null)

kMDItemFSInvisible = 0

kMDItemFSIsExtensionHidden = 0

kMDItemFSIsStationery = (null)

kMDItemFSLabel = 0

kMDItemFSName = "alex-arriaga.png"

kMDItemFSNodeCount = (null)

kMDItemFSOwnerGroupID = 20

kMDItemFSOwnerUserID = 501

kMDItemFSSize = 8305

kMDItemFSTypeCode = ""

kMDItemHasAlphaChannel = 0

kMDItemKind = "Portable Network Graphics image"

kMDItemLogicalSize = 8305

kMDItemOrientation = 0

kMDItemPhysicalSize = 12288

kMDItemPixelCount = 36000

kMDItemPixelHeight = 180

kMDItemPixelWidth = 200

kMDItemResolutionHeightDPI = 72

kMDItemResolutionWidthDPI = 72

kMDItemWhereFroms = (

"http://www.alex-arriaga.com/wp-content/themes/fenix/img/alex-arriaga.jpg",

)

That’s it for today, see you next time!

alex-arriaga July 6, 2014

Some useful Git commands

GNU/Linux, Mac OSX, Operating Systems, Windows 1 Reply

Hi friends,

Today I would like to share you a list of Git commands that I consider really useful when we work with this great version control system. Enjoy it!

Configuring your Git

// Disable autocrlf to avoid warnings in command line
git config --global core.autocrlf false

1 2	// Disable autocrlf to avoid warnings in command line git config --global core.autocrlf false

// Set username and email (global)
git config --global user.name “My user name” 
git config --global user.email “my-email@awesome.com” 

// Display configuration
git config -l 

// Get some help :)
git contig -h

// Set username and email (global)

git config --global user.name “My user name”

git config --global user.email “my-email@awesome.com”

// Display configuration

git config -l

// Get some help :)

git contig -h

Managing Git repositories

Initializing a repo

git init

git init

Adding files for tracking or to the staging area

// Add all .txt files
git add *.txt

// Add all in the current directory
git add .

// Add a single file
git add README.md

// Add all .txt files

git add *.txt

// Add all in the current directory

git add .

// Add a single file

git add README.md

Resetting your files in the staging area to the working directory

git reset HEAD <file>
git reset HEAD -- <path/to/file>

// Examples
git reset HEAD index.html
git reset HEAD .

git reset HEAD <file>

git reset HEAD -- <path/to/file>

// Examples

git reset HEAD index.html

git reset HEAD .

Doing your changes persistent in the local repository

// Do a commit with all files in staging area
git commit -m "My custom message for this commit"

1 2	// Do a commit with all files in staging area git commit -m "My custom message for this commit"

Watching previos version of files

// Watch a version of a very specific file (using the commit ID)
git checkout YOUR_COMMIT_ID -- path/my_file.js

// Return to the version of that file in HEAD
git checkout HEAD -- path/my_file.js

// Watch a version of a very specific file (using the commit ID)

git checkout YOUR_COMMIT_ID -- path/my_file.js

// Return to the version of that file in HEAD

git checkout HEAD -- path/my_file.js

Watching logs

// Watch the log (details)
git log 

// Watch the log in one line per commit
git log --oneline 

// See two last commits
git log --oneline -2

// Show diff between files
git show

// Watch the log (details)

git log

// Watch the log in one line per commit

git log --oneline

// See two last commits

git log --oneline -2

// Show diff between files

git show

Merging a branch (my-branch) into other (master)

// Where do you want to merge?
git checkout master

// Which branch do you want to merge?
git merge my-branch

// Where do you want to merge?

git checkout master

// Which branch do you want to merge?

git merge my-branch

Restoring files

See the stored version of an specific file in a commit:

git checkout COMMIT_ID "path/to/the/file"

// Example
git checkout 6881326  "widgets/Awesome Widget/MyAwesomeWidget.dust.tpl.htm"

git checkout COMMIT_ID "path/to/the/file"

// Example

git checkout 6881326 "widgets/Awesome Widget/MyAwesomeWidget.dust.tpl.htm"

Working with branches

Creating, deleting and switching to a branch

// Get a list of branches in the repository
git branch

// Create a new branch
git branch my-branch

// Switch to a branch
git checkout my-branch

// A shorthand for two previous commands (create and switch)
git checkout -b other-branch 

// Delete a branch
git branch -d my-branch

// Get a list of branches in the repository

git branch

// Create a new branch

git branch my-branch

// Switch to a branch

git checkout my-branch

// A shorthand for two previous commands (create and switch)

git checkout -b other-branch

// Delete a branch

git branch -d my-branch

Working with submodules

A very nice feature available on git is the possibility of using modules, for example when you clone CakePHP repository you could get DebugKit as a submodule, if you want to clone the main repository + submodules, use following command:

git clone --recursive https://github.com/alex-arriaga/universidad-del-pastel.git

1	git clone --recursive https://github.com/alex-arriaga/universidad-del-pastel.git

Adding a new submodule

git submodule add <GIT_REPO_URL> <SUBMODULE_NAME>
 
// Example
git submodule add https://github.com/twbs/bootstrap.git bootstrap

git submodule add <GIT_REPO_URL> <SUBMODULE_NAME>

// Example

git submodule add https://github.com/twbs/bootstrap.git bootstrap

If someone else added a new submodule, and you want to get submodules, you will need to use the update operation to obtain the module recently added:

git submodule update --init --recursive

1	git submodule update --init --recursive

Changing a submodule for another one

Update .gitmodules with the path to the new repository
Remove the corresponding line from the “.git/config” file
Delete the corresponding directory in the “.git/modules/modules/YOUR_OLD_SUBMODULE” directory (rm -rf)
Delete the checked out submodule directory itself (unsure if this is necessary)
Run:

git submodule init and git submodule update

1	git submodule init and git submodule update

Make sure the checked out submodule is at the correct commit, and commit that, since it’s likely that the hash will be different

Working with remotes

Forcing a push in origin (remote) to a previous version as in our local repository

// Suppose you want to return to a previous version
// in your local repository
git reset --hard YOUR_COMMIT_ID

// Then, probably you will need to force the remote to stay 
// in the same as your local repository
git push origin master --force

// Or
git push origin master -f

// Suppose you want to return to a previous version

// in your local repository

git reset --hard YOUR_COMMIT_ID

// Then, probably you will need to force the remote to stay

// in the same as your local repository

git push origin master --force

// Or

git push origin master -f

Sometimes if the remote server doesn’t have well-configured SSL certificates, you could get an error. If you want to disable SSL verification which I don’t recommend, use next command:

// Disable the SSL CERT verify globally
git config --global http.sslVerify false

// Disable the SSL CERT verify only in current repository
git config http.sslVerify false

// Disable the SSL CERT verify globally

git config --global http.sslVerify false

// Disable the SSL CERT verify only in current repository

git config http.sslVerify false

Changing the URL of a remote:

git remote set-url <REPOSITORY_NAME> <NEW_URL>

// Example
git remote set-url origin git://new.url.here

git remote set-url <REPOSITORY_NAME> <NEW_URL>

// Example

git remote set-url origin git://new.url.here

Deleting remote branches

// List all the branches (local and remote)
git branch -a

// Delete a branch
git push origin --delete MY_BRANCH

// List all the branches (local and remote)

git branch -a

// Delete a branch

git push origin --delete MY_BRANCH

alex-arriaga June 13, 2014

Session 4 – grep command (UNIX and Linux commands, in Spanish)

GNU/Linux, Mac OSX, Operating Systems No Reply

In my life as a front-end and back-end developer, I am searching for very specific strings in thousands of files and directories, so one of my favorite commands in UNIX and Linux is the grep command. This awesome command is able to find complex strings based on patterns.

Watch this video and learn how to use and make your life easier. Enjoy and share the video, and remember be happy with your console!

alex-arriaga June 13, 2014

Session 3 – mkdir command (UNIX and Linux commands, in Spanish)

GNU/Linux, Mac OSX, Operating Systems No Reply

How many times do you create directories (folder) in your computer? I know for sure this is one of the most frequent operations in daily work, right? What about if I tell you there is a great command for UNIX and Linux for fast creation of any directory or directories you want!

Well, watch this video and become in a master of creation of directories. Enjoy and share if you liked it!

alex-arriaga June 13, 2014

Session 2 – chmod command (UNIX and Linux commands, in Spanish)

GNU/Linux, Mac OSX, Operating Systems 1 Reply

A very common operation in UNIX-like and Linux operating systems is to set permissions to files and directories, I have seen many people suffering because of these permissions, so today I am going to explain you how to use the chmod command, with this command you will be able to modify any permissions in the file system.

So, let´s start with the video I hope you find it useful for your daily work. Enjoy it!

alex-arriaga June 13, 2014

Session 1 – ls command (UNIX and Linux commands, in Spanish)

GNU/Linux, Mac OSX, Operating Systems 1 Reply

Console-128

This is the first video about UNIX and Linux commands, in this session we are going to learn how to use the ls command which allows us to get a list directories and files. Enjoy and share this video, and remember be happy with your code!

alex-arriaga May 6, 2014

How to rename files recursively deleting white spaces in file names with shell script

GNU/Linux, Mac OSX, Operating Systems No Reply

Hi!

Today, I would like to share a small script (in shell) to rename files recursively but replacing white spaces in the files’ names. For this task I have only used standard commands in order to be sure this script will work on any GNU/Linux or UNIX-like operating system (mv, sed, find,..). Enjoy and personalize this script as you need!

# Finding all files in a directory and its children
path_to_images="/Users/alex/Downloads/images"

find $path_to_images -type f -name *.jpg -follow |
while read -r file;
do
	file_name="${file##*/}"
	directory=$(dirname "$file")

	# Delete all the whitespaces in file name using sed
	new_file_name=$(echo $file_name | sed 's/ /-/g')
	new_path=$directory'/'$new_file_name
	mv "$file" "$new_path";
	echo "Renamed: $new_path"
done

# Finding all files in a directory and its children

path_to_images="/Users/alex/Downloads/images"

find $path_to_images -type f -name *.jpg -follow |

while read -r file;

file_name="${file##*/}"

directory=$(dirname "$file")

# Delete all the whitespaces in file name using sed

new_file_name=$(echo $file_name | sed 's/ /-/g')

new_path=$directory'/'$new_file_name

mv "$file" "$new_path";

echo "Renamed: $new_path"

done

Most important lines are:

find $path_to_images -type f -name *.jpg -follow

1	find $path_to_images -type f -name *.jpg -follow

Which obtains all the files with .jpg extension starting from $path_to_images, and these other lines:

new_file_name=$(echo $file_name | sed 's/ /-/g')
new_path=$directory'/'$new_file_name

1 2	new_file_name=$(echo $file_name \| sed 's/ /-/g') new_path=$directory'/'$new_file_name

Which replace all white spaces for a dash “-“, in the current $file_name and then by using the mv command the renaming operation is executed.

That’s it!

Be happy with your code!

alex-arriaga April 20, 2014

Open directories with Sublime Text 2 using the command line (Mac OSX)

Mac OSX, Operating Systems 1 Reply

What about this: imagine if you could open your great Sublime Text 2 editor in a specific directory from the command line, well, today, I would like to share you the easiest way to configure that useful task in your Mac OSX. It is really simple, it just a matter of creating a symbolic link (a kind of direct access) to the subl executable.

Next line do the task for you:

sudo ln -s "/Applications/Sublime Text 2.app/Contents/SharedSupport/bin/subl" /usr/local/bin/subl

1	sudo ln -s "/Applications/Sublime Text 2.app/Contents/SharedSupport/bin/subl" /usr/local/bin/subl

Once you have created the symbolic link, open a Terminal and run following command:

> subl directory_to_open
// Example: open my Desktop folder in Sublime Text 2
> subl /Users/alex/Desktop

> subl directory_to_open

// Example: open my Desktop folder in Sublime Text 2

> subl /Users/alex/Desktop

That’s it! Now you can open any directory using the command line.

What would you like to know about?

Alex Arriaga

Category Archives:
Operating Systems

Solving Drupal error: PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away

The problem

Solution

SOLVED: Git remote ref does not exist when trying to delete branches

The problem

Solution

How to get metadata of images in Mac OSX

An great tool

Another option (bad option)

Some useful Git commands

Configuring your Git

Managing Git repositories

Restoring files

Working with branches

Working with submodules

Working with remotes

Session 4 – grep command (UNIX and Linux commands, in Spanish)

Session 3 – mkdir command (UNIX and Linux commands, in Spanish)

Session 2 – chmod command (UNIX and Linux commands, in Spanish)

Session 1 – ls command (UNIX and Linux commands, in Spanish)

How to rename files recursively deleting white spaces in file names with shell script

Open directories with Sublime Text 2 using the command line (Mac OSX)

Join me, have fun and learn!

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What would you like to know about?

Category Archives:Operating Systems

The problem

Solution

The problem

Solution

An great tool

Another option (bad option)

Configuring your Git

Managing Git repositories

Restoring files

Working with branches

Working with submodules

Working with remotes

Join me, have fun and learn!

Tag Cloud

Recent Posts

Recent Comments

Join me, have fun and learn!

Recent Posts

Day quote…

Recent Comments

Categories

Tag Cloud

Archives

Join me, have fun and learn!

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Archives

Tag Cloud

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Categories

Category Archives:
Operating Systems