Shell Scripting
Last updated: 2020-05-03
Add git branch name to bash prompt
Add following lines to your ~/.bash_profile
parse_git_branch() {
git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}
export PS1="\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $ "
In here parse_git_branch() function extract the branch name when your are in git repository. This function output used in PS1 variable in order to prompt the branch name.
In above PS1 we defined following properties:
\u@\h \[\033[32m\]- user, host name and its displaying color\w\[\033[33m\]- current working directory and its displaying color\$(parse_git_branch)\[\033[00m\]- git branch name and its displaying color
Now when you go to git repository form the terminal it will display currently checked out git branch in the prompt. Following is the example output of bash prompt after adding these changes to ~/.bash_profile.
My Bash Prompt
export PS1="\W\$(parse_git_branch)\[\033[00m\] $ "
Colors
Foreground & background colour commands
tput setab [1-7] # Set the background colour using ANSI escape
tput setaf [1-7] # Set the foreground colour using ANSI escape
Colours are as follows:
Num Colour #define R G B
0 black COLOR_BLACK 0,0,0
1 red COLOR_RED 1,0,0
2 green COLOR_GREEN 0,1,0
3 yellow COLOR_YELLOW 1,1,0
4 blue COLOR_BLUE 0,0,1
5 magenta COLOR_MAGENTA 1,0,1
6 cyan COLOR_CYAN 0,1,1
7 white COLOR_WHITE 1,1,1
There are also non-ANSI versions of the colour setting functions (setb instead of setab, and setf instead of setaf) which use different numbers, not given here.
Text mode commands
tput bold # Select bold mode
tput dim # Select dim (half-bright) mode
tput smul # Enable underline mode
tput rmul # Disable underline mode
tput rev # Turn on reverse video mode
tput smso # Enter standout (bold) mode
tput rmso # Exit standout mode
Clear and insert commands
tput ech N # Erase N characters
tput clear # Clear screen and move the cursor to 0,0
tput el 1 # Clear to beginning of line
tput el # Clear to end of line
tput ed # Clear to end of screen
tput ich N # Insert N characters (moves rest of line forward!)
tput il N # Insert N lines
Other commands
tput sgr0 # Reset text format to the terminal's default
tput bel # Play a bell
Example
red=`tput setaf 1`
green=`tput setaf 2`
reset=`tput sgr0`
echo "${red}red text ${green}green text${reset}"
Arrays
Make Directory
mkdir directory_name
# -p flag will make directory if it does not already exist
mkdir -p directory_name
CURL
curl http://pathtofile.xml -o ~/Desktop/output_filename.xml
SCP
The basic format of the command:
scp [options] original_file destination_file
To format the remote portion:
user@server:path/to/file
Note: to copy whole directories use the [-r] flag
Symbolic Link
ln -s <path_to_file_that_should_be_linked> .
Symbolic link to all files in a folder (OSX)
ln -s <path_to_file_that_should_be_linked/*> .
To check if a symbolic link exists before creating:
cdn=../cdn
path=../build
files=( "docs" "fonts" "media" "ui")
for i in "${files[@]}"
do
if [[ -h "$path/$i" ]]; then echo "{$i} link exists"; else ln -s "$cdn/$i" "$path/$i"; fi
done
This will loop through the defined path and check each of the items in the files array to see if they exist as a symbolic link. If they do not exist, the script will create the symlinks.
File copy maintaining Date/Owner info
cp -a path/filename
Open files in specific apps
http://hints.macworld.com/article.php?story=2004012218171997
open -a "Adobe Photoshop 7.0" foo.jpg
Directory compare and txt list output
Compare directories and export txt list of differences:
diff -qr dirA dirB | grep -v -e 'DS_Store' -e 'Thumbs' | sort > diffs.txt
List contents of zipped file
To list contents of zipped file:
unzip -l filename.zip
Copy
cd /destination of copy/
cp -R /directory_files to copy .
Copy With Preservation
$ cp -rp /source /destination
#
# cp manpage details
-p same as --preserve=mode,ownership,timestamps
--preserve[=ATTR_LIST]
preserve the specified attributes (default: mode,ownership,timestamps),
if possible additional attributes: context, links, xattr, all
Batch Rename
for file in *.zipd; do mv "$file" "${file%zipd}zip"; done
Batch Remove Spaces In File Names
#! /bin/sh
for n in *
do
OldName=$n
#NewName=`echo $n | tr -d " "`
NewName=`echo $n | tr -s " " "-"`
echo $NewName
mv "$OldName" "$NewName"
done
To run this script, cd into the destination directory and then execute. Example:
cd directory/my-files/
~/Documents/./remove-spaces *
Create Executable Shell Script
$ ls
myscript.sh
$ mv myscript.sh myscript
$ chmod 755 myscript
# To use the script from the command line:
$ ./myscript
Find & Remove Files Based On Wildcard String
NEEDLE represents the wildcard string value that is being searched for in the file names.
find . -maxdepth 1 -name "*NEEDLE*" -print
find . -maxdepth 1 -name "*NEEDLE*" -exec rm {} \;
Show files by edit date
List files edited in the past day
find . -type f -newermt 2011-06-07
find . -type f -newermt 2011-06-06 ! -newermt 2011-06-07 | sort > ~/Desktop/list.txt
Outgoing IP address
curl ifconfig.me
Network Commands
Extract files from multiple folders
find path/to/extract/from -name *.mp3 -exec cp {} /path/to/destination \;
sftp / ssh
To access a remote server without the use of a public key use:
ssh -o "PubkeyAuthentication no" user@server
sftp -o "PubkeyAuthentication no" user@server
Get User Input
echo "Type something and then hit [ENTER]"
read userinput
Does directory exist
if [ -d "$dir" ]
then
echo "$dir directory already exists!"
else
echo "$dir directory not found!"
fi
Recursively Remove 'node_modules' Directories
find . -name "node_modules" -type d -prune -exec rm -rf '{}' +
Some helpful ftp commands
- pwd: print working directory of remote host
- lpwd: print working directory of local host
- cd: change directory of remote host
- lcd: change directory of local host
- ls: list directory on the remote host
- lls: list directory on the local host
- mkdir: make directory on remote host
- lmkdir: make directory on local host
- get: receive file from remote host to local client
- put: send file from local client to remote host
- help: display help text
Reformat Text As A Long List of Words
tr [:cntrl:] " " <filename | tr -s " " >new.filename
Insert a new line every ten words
xargs -n10 < file
# output to a new file
xargs -n10 < new.file
Package Assets
#!/bin/bash
cd ${0%/*}
# Package `build` contents for delivery.
read -r -p "Package for delivery? (did you --production flag everything?) [Y/n] " response
case $response in
[yY][eE][sS]|[yY])
echo 'Copying files...'
cp -r ../build ~/Desktop/.
cd ~/Desktop/
mv build package_name
echo 'Done.'
echo 'Zipping files...'
zip -r9X package_name.zip package_name
echo 'Done.'
read -r -p "Delete prep directory? This will leave the .zip file but remove the temporary source. [Y/n] " response
case $response in
[yY][eE][sS]|[yY])
echo 'Cleaning up...'
rm -r package_name
;;
esac
cd -
echo 'Packaging complete.'
open ~/Desktop/
;;
*)
# do_something_else
;;
esac