Entries Categorized as 'How-To’s'

How To Select Rows in MySQL with No Matching Entry in Another Table

Author: , May 16th, 2018

SELECT t1.id FROM tableOne t1 LEFT JOIN tableTwo t2 ON t1.id = t2.id WHERE t2.id IS NULL The “WHERE t2.id IS NULL clause” restricts the results to only those rows where the id returned from tableTwo is null. tableTwo.id will be NULL for all records from tableOne where the id is not found in tableTwo.

How To Move Around in Linux CLI Mail

Author: , May 7th, 2018

h Shows you a screenful of message headers (a “header” being the number, sender, date, size and subject). h with no message number shows the current screenful of messages (the number that make up a screenful is set with the screen variable, described below). h$ shows you the last screenful of messages — which is […]

How To Locate Attached Disk Devices in Linux

Author: , April 24th, 2018

https://linux.die.net/man/8/lsblk # lsblk -a 1 2 3 4 5 NAME          MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT nvme1n1       259:0    0  100G  0 disk /volumes/data nvme0n1       259:1    0   20G  0 disk ├─nvme0n1p1   259:2    0   20G  0 part / └─nvme0n1p128 259:3   […]

How To Move in vim Using the Keyboard

Author: , March 21st, 2018

h move one character left j move one row down k move one row up l move one character right w move to beginning of next word b move to previous beginning of word e move to end of word W move to beginning of next word after a whitespace B move to beginning of […]

How To Scroll to the Top of the Page using Javascript

Author: , March 20th, 2018

window.scrollTo(x-coord, y-coord); Example: window.scrollTo(0,0);

How To Expand a Filesystem on AWS Linux

Author: , March 6th, 2018

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/recognize-expanded-volume-linux.html This only works on the new expandable volumes. YMMV, as always. 1. Examine file -s /dev/xvd* lsblk df -h 2. Grow partition Expand the modified partition using growpart (and note the unusual syntax of separating the device name from the partition number): growpart /dev/xvda 1 lsblk 3. Expand filesystem resize2fs /dev/xvda1 df -h

How To Strip Windows Newlines in PHP

Author: , February 21st, 2018

$text = str_replace(“\r”, “”, $text);

How To Create and Restore an SVN Backup Dump File (.dmp)

Author: , February 1st, 2018

Backup Compressed: svnadmin dump /volumes/data/svn/yourRepo | gzip -9 > /volumes/data/backup/yourRepo.dmp.gz Backup Uncompressed: svnadmin dump /volumes/data/svn/yourRepo > /volumes/data/backup/yourRepo.dmp Restore the Repo Create a new SVN repository: svnadmin create /volumes/data/svn/newRepo Restore the dump file to the new repository: svnadmin load /volumes/data/svn/newRepo < /volumes/data/backup/yourRepo.dmp Just for good measure, here is how to checkout from a local repo: svn […]

How To Rename a Branch in Git Locally and Remotely

Author: , January 31st, 2018

Rename the old branch locally: git branch -m oldBranch newBranch Delete the old branch remotely: git push origin :oldBranch Push up the new branch, and make the local branch track with the new remote branch: git push –set-upstream origin newBranch

How To Remove a Package Without the Dependencies (yum/rpm)

Author: , January 9th, 2018

To remove a specific package without its dependencies use rpm: 1 2 rpm -qa | grep pecl rpm -e –nodeps php55-pecl-jsonc php55-pecl-jsonc-devel rpm -qa | grep pecl rpm -e –nodeps php55-pecl-jsonc php55-pecl-jsonc-devel As always, YMMV!