abechoi/shell_scripting

Shell scripting with ZSH and BASH

https://www.youtube.com/watch?v=tK9Oc6AEnR4&ab_channel=freeCodeCamp.org

Create Text File

1. Create file vim textfile.txt

   a. Type i to enter Insert mode
   b. Enter Hello World!
   c. Hit esc, then enter :qw to write and quit
   d. Output file cat textfile.txt

Hello World

2. Create file vim shellscript.sh

   a. Type a to enter Append mode, which outputs character after cursor
   b. Enter echo Hello World!
   c. Hit esc, then enter :qw to write and quit
   d. Run script zsh [shelltest.sh](http://shelltest.sh) or bash shelltest.sh

Run Script without ZSH or BASH Command

3. Modify file vim shellscript.sh

   #!/bin/zsh
   echo Hello World!

   a. modify permissions chmod u+x shellscript.sh b. Run script ./shellscript.sh

Variables

#!/bin/zsh

## BAD
cp /my/location/from /my/location/to
cp /my/location/from/here /my/location/to/there

## GOOD

MY_LOCATION_FROM=/my/location/from
MY_LOCATION_TO=/my/location/to

cp $MY_LOCATION_FROM $MY_LOCATION_TO
cp "$MY_LOCATION_FROM" "$MY_LOCATION_TO"

4. Create file vim hellothere.sh

   #!/bin/zsh
   FIRST_NAME=Abraham
   LAST_NAME=Choi
   
   echo Hello $FIRST_NAME $LAST_NAME

   a. modify permissions chmod u+x hellothere.sh b. Run script ./hellothere.sh

Arguments

5. Create file vim interactive.sh

   #!/bin/zsh
   
   echo "What is your first name?"
   read FIRST_NAME
   echo "What is your last name?"
   read LAST_NAME
   
   echo Hello $FIRST_NAME $LAST_NAME

   a. modify permissions chmod u+x interactive.sh b. Run script ./interactive.sh

6. Create file vim posargs.sh

   #!/bin/zsh
   
   echo Hello $1 $2

   a. modify permissions chmod u+x posargs.sh b. Run script ./posargs.sh [ARG 1] [ARG 2]