mirror of https://github.com/deajan/obackup.git
148 lines
4.7 KiB
Plaintext
148 lines
4.7 KiB
Plaintext
Coding style used for my bash projects (v2.1 Oct 2015)
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++++++ Header
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Always use the following header
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----BEGIN HEADER
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#!/usr/bin/env bash
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PROGRAM="program-name" # Long description
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AUTHOR="(L) 20XX-20YY by Orsiris \"Ozy\" de Jong"
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CONTACT="http://www.example.com me@example.com"
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PROGRAM_BUILD=YYYYMMDDVV
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## Optional instructions
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----END HEADER
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Using bind style versionning:
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YYYYMMDDVV (Year, Month, Day, Revision): Example: 2015012402 = 2nd revision of 24 Jan 2015
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#!/usr/bin/env bash instead of #!/bin/bash
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Change old scripts with
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for i in $(grep -r '#!/bin/bash' * |cut -f1 -d':'); do sed -i 's&#!/bin/bash&#!/usr/bin/env bash&g' $i; done
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type instead of type -p for bash test (other shells don't know -p)
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++++++ Indentation
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Using tabs
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Transform old shell scripts using unexpand command
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++++++ Comments
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Some command # comment
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## Some comment on a new line
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################################################# Some separation
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++++++ Work comments
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Whenever there is some idea to postpone, use #TODO[-version]:[dev-name:] some remark
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A marker must be left where on the line a dev is working (when the work isn't finished). Marker is #WIP:dev-name: some remark
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dev-name is mandatory if more than one person is coding
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Example: #TODO-v2.1:deajan: need to do something
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++++++ Variables
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All local variables are lowercase, separated by _ (ex: low_wait)
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All global variables full upercase, separated by _ (ex: EXEC_TIME)
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All environment variables (verbose, silent, debug, etc) have prefix _ and are full upercase, separated by _ (ex: _PARANOIA_DEBUG)
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++++++ Functions
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Every word in a function begins with an uppercase (ex: SomeFunctionDoesThings)
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Define functions this way. Use sed ':a;N;$!ba;s/\n{\n/ {\n/g' to adapt when opening bracket is on a new line.
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function something {
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}
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If function has some arguments, use local variable names that are more readable than $1...$n. Explain via comments what those variables contain if needed.
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function anotherthing {
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local var_name="${1}"
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local other_var_name="${2}" # This variable contains stuff
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}
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Functions should always have return status
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function thirdthing {
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some_command
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return $?
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}
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++++++ Sub functions
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When a function is a subroutine of another function, it is called _SomethingAsSubFunction
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++++++ Function argument check
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Bash does not provide any checks against missing function arguments. Also, missing quotes can lead to an inconsistent number of arguments.
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Every function call will be checked by __CheckArguments which takes the number of arguments, $# (the real number of args given), the parent function name and the parent function's arguments.
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__CheckArguments will trigger a critical error if number of arguments if incorrect. This will also prevent silent typo errors.
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Ex:
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function Something {
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local some="${1}"
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local other="${2}"
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local args="${3}"
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__CheckArguments 3 $# $FUNCNAME "$*"
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__CheckArguments will only trigger if script is called with DEBUG=yes
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Also, with PARANOIA_DEBUG=yes, __CheckArguments will recount all arguments given by "$*" and compare. This can mislead if arguments contain spaces.
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++++++ If statements
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If statements will be fully written (word "if" must be used). then is written on the same line.
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(Use sed ':a;N;$!ba;s/]\n\t*then/]; then/g' to convert files to this format... Replace "],new line, zero or more tabs, then" by "; then")
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if [ something ]; then
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stuff
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else
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other stuff
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fi
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++++++ Logging
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A logging function is available with the following levels of logging:
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- DEBUG: Only log this when DEBUG flas is set in program. Any command forged for eval should be logged by this.
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- NOTICE: Standard messages
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- WARN: Requires attention
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- ERROR: Program produced an error but continues execution
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- CRITICAL: Program execution is halted
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++++++ Eval
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Most commands should be logged to a tmp file.
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The basic way of doing is:
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cmd='"something '$somevar'" > some_file 2>&1'
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eval $cmd &
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WaitForTaskCompletion $! 0 0 $FUNCNAME
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Remote commands should exist as:
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cmd=$SSH_CMD' "some; commands \"'$VARIABLE'\" some; other; commands" > some_file 2>&1'
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++++++ File variables
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All eval cmd should exit their content to a file called "$RUNDIR/osync.$FUNCNAME.$SCRIPT_PID"
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Dots are used instead of '_' so variables can be separated with a forbidden char in variables, so they get detected.
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++++++ Finding code errors
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Use shellcheck.net now and then (ignore SC2086 in our case)
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Use a low tech approach to find uneven number of quotes per line
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tr -cd "'\n" < my_bash_file.sh | awk 'length%2==1 {print NR, $0}'
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tr -cd "\"\n" < my_bash_file.sh | awk 'length%2==1 {print NR, $0}'
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++++++ ofunctions
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As obackup and osync share alot of common functions, ofunctions.sh will host all shared code.
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Dev programs n_osync.sh and n_obackup.sh will source ofunctions.sh
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Release programs will still include ofunctions.sh in order to enhance ease of use.
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