_shell

Shell in a nutshell 🌰

• Config Files
• Syntax
• Commands
• Setting Aliases
• Scripting
• WSL

Config

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used for saving aliases, setting enviroment variables, etc.

Bash

• linux: /usr/<username>/config/cshrc.csh
• macOS: /Users/<username>/.bash_profile

Batch

1. create a .bat file with aliases commands, ie. aliases.bat
2. in cmd, run regedit and go to:
   • before windows 10: HKEY_CURRENT_USER\Software\Microsoft\Command Processor
   • in windows 10: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Command Processor
3. add String Value entry, with name AutoRun
4. set its value to full path of aliases.bat

online ref

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Syntax

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Bash

• variables: NAME="potato", $NAME, ${NAME:6:7}
• arguments: $[1-9]
  • $#: number of arguments
  • $*: all arguments (list)
• comments: #Comments
• options: -o

Batch

• variables: %VARIABLE%
• argument: %<1-9>
• comments: :: or Rem
• switch: /<a-z>
• other:
  • @: apply command to itself, ie. @echo off: to turn off display of commands
  • >: redirect output, ie. dir in > out

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Commands

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Bash

• ls: list contents of a directory
• cd: change directory
• export: sets script variables
• setenv: sets enviroment variables
• echo: prints in shell
• clear: clear shell
• start: start a program
• mkdir: make directory
• printenv: display enviroment variables
• alias: sets aliases
• man <cmd>: prints Manual for <cmd>

Batch

• dir: list contents of a directory
• cd: change directory, d:: change drive
• set: sets variables, or display enviroment variables
• echo: prints in shell
• cls: clear shell
• start: start a program
• md: make directory
• path: display or sets %PATH% variable
• rem: comments
• doskey: sets aliases or macros
• pause: pause shell from auto-close after successfully execute script

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Setting Aliases

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Bash

• c-shell: alias <aliasname> '<command>'
• bash-shell: alias <aliasname>='<command>'

Batch

doskey <aliasname>="command" $[1-9]

using command-line argv with doskey aliases (tricky one)

you have to tell the alias how many argument this doskey macro will have, doskey documentation

• in aliases.bat
  • doskey aliases="file.bat" $1 $2 $3...
• in file.bat
  • $[1-9] = %[1-9]

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Scripting

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Bash

Batch

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