Bash Scripting Training Content
Day 1
- Linux basics
- Bash introduction
- Essential tools you need to know
- List of commands
Day 2
- Special variables
- $#, $0, $n, $$, $?, $!, $@/$*
- Arrays
- Programming Structures
- Essential tools you need to know - Part 2
- sort, uniq, find, cut, awk, sed
- tr, xargs, which
Day 3
- Redirections
- stdin, stdout, stderr, tee, /dev/null, /dev/fd/0
- /dev/stdin, /dev/tcp/host/port
- Functions
- Bash export functions
- Declare -fx foo
- Pipes
- Status and Exit codes
- 0 and 255
- syscall responder
waitpid
- Error management and debugging
- -eux, trap, echos
- –debugger (bashdb)
Day ?
- Math
- Calculations with bc
- Convert oct, hexa to dec
- Declare -i 16 i=255
- Declare -F 3 x=‘1.0/3’ # or -E
- Jobs
- jobs, fg, bg
- Jobs, ctrl z, fg %1, bg %1, stop %1
- Shell expansions
- REVIEW: https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html#Special-Parameters
- Brace expansion: mkdir ~/tmp/{a,b,c}.txt
- Parameter expansion: ${var:=default}, ${var:?var is unset or null}
- Parameter offsets: ${parameter:offset:length}
- Patterns
- User ${HOME##*/} or %% vs ##
- Expanders
- Expansion flags: uppercase
- Mv $f ${(L)f}
- Strings management
- A=1234567890
- ${A:2:3}
- Braces multiple options, gen numbers, alphabet,
- Groups and subshells
- <() >() $()
- () vs {}
- {Sleep 5; make; } &
- Bash autocompletion
Labs:
- Cool bash functions:
- Most big files or directories function
- Most consuming mem app
- Aws cli jq: list users
- Gcloud yq: list instances
- Docker cli cleanup
- Git: tricks
- Extract parse html data: curl
- Curl and JSON payloads
- FFmpeg:
- YouTube dl
- Convert mp4 to mp3 ffmpeg
- Compress images
- Nmap ssl lib?, openssl cli download certificate
Others:
- Signals
- ulimit
- POSIX
Complementary:
- Bash builtin functiosn