Revision as of 21:55, 10 February 2017

Trouble Shooting:

• Start with the basics...like power, network, etc.

General:

• Know the animal before trying to tame
• Some vendors use MB/GB (decimal...1000s) and some use MiB/GiB (binary...1024s)
• Always query before running modification command(s)
• Backup or already have a backup before modifying files
• Learn your editor(s) well...it's functions can save a ton of time
• Always tail -f error logs when developing

Development:

• Naming
  • Avoid spaces.
  • Use camelCase.
  • Name common items with the common word starting each item.
  • Name same item, but numbered with enough padding to sort correctly. ex: if going to at least 10 use 01-10 instead of 1-10.
  • Name date by number not name and most general to specific. So they sort correctly. ex: 20161231 instead of Dec31-2016, etc.
  • Name using noun first then verb. ex: logCreate, logList, dateStart, dateEnd, etc.

• Coding
  • Top-down vs bottom-up design
  • Always add comments...you may not remember what you did day, months, years from now
  • Line up block brackets up vertically
  • Happy balance between elegance/complexity and readability/maintainability
  • Happy balance between too long and too short variable naming
  • Pick a style and stay consistent...this sometime means following someone else's style when modifying existing code
  • Learn your debugging tool(s)...they can save a ton of time
  • Give some thought to designing your log files...
    • Put the date and time in each record
    • Format well...XML, JSON, delimited, etc.
    • Make sure enough data is included to be helpful

*nix:

• Type "env" in the shell to display all the environment variables
• Use "set -x" to debug shell scripts ("set +x" turns it off)
• Use "set -o vi" to use vi to navigate/modify shell commands ("set +o" turns it off)
• crontab
  • Put number in 09 format to make easier to read, parse and sort
  • Always redirect command output somewhere, log file, /dev/null, etc., so it does not fill up your email

SQL:

• Always use a where clause even if for everything...where 1 or where 1 = 1. This reminds someone editing the code that this query is operating on EVERYTHING.
• Comments are handy even in SQL for debugging and as comments. "--comments" is universal, but also /* comments */ in MySQL, {comments} in Informix, etc.