Bash functions store a series of commands for later execution. If you find yourself running a sequence of commands frequently, it would make sense to wrap them up in a function. Functions are a lot like aliases but you can also pass arguments to them.
Update: My dotfiles are now in Git. For the latest version, please visit my GitHub dotfiles repository.
Here is a list of my bash functions taken from ~/.bash_functions.
#
# Go up a specified number of directories
#
up(){
if [ -z $1 ]
then
cd ..
return
fi
local levels=$1
local result="."
while [ $levels -gt 0 ]
do
result=$result/..
((levels--))
done
cd $result
}
#
# Make a directory and change to it
#
mkcd(){
if [ $# -ne 1 ]; then
echo "Usage: mkcd <dir>"
return 1
else
mkdir -p $1 && cd $1
fi
}
#
# fast find, using globstar
#
ff(){
ls -ltr **/$@
}
#
# Jumps to a directory at any level below.
# using globstar
#
jd(){
if [ -z $1 ]; then
echo "Usage: jd [directory]";
return 1
else
cd **/$@
fi
}
#
# moves file to ~/.Trash
# (use instead of rm)
#
trash(){
if [ $# -eq 0 ]
then
echo Usage: trash FILE...
return 1
fi
local DATE=$(date +%Y%m%d)
[ -d "${HOME}/.Trash/${DATE}" ] || mkdir -p ${HOME}/.Trash/${DATE}
for FILE in "$@"
do
mv "${FILE}" "${HOME}/.Trash/${DATE}"
echo "${FILE} trashed!"
done
}
#
# Calculate an expression e.g. calc 1+1
#
calc(){
echo "$@"|bc -l;
}
#
# Calendar which starts on Monday
# Highlights current day
#
cal(){
if [ $# -eq 0 ]
then
/usr/bin/cal -m | sed "s/\($(date +%e)\)/${RED}\1${NONE}/"
else
/usr/bin/cal -m "$@"
fi
}
#
# Email me a short note
#
emailme(){
if [ $# -eq 0 ]
then
echo Usage: emailme text
return 1
fi
echo "$*" | mailx -s "$*" fahds
echo "Sent email"
}
#
# Prints out a long line. Useful for setting a visual flag in your terminal.
#
flag(){
echo -e "\e[1;36m[==============="$@"===\
($(date +"%A %e %B %Y %H:%M"))\
===============]\e[m"
}
#
# Swap two files
#
swap(){
if [ $# -ne 2 ]
then
echo Usage: swap file1 file2
return 1
fi
local TMPFILE=tmp.$$
mv "$1" $TMPFILE
mv "$2" "$1"
mv $TMPFILE "$2"
}
#
# Backup file(s)
#
dbackup(){
if [ $# -lt 1 ]
then
echo Please supply a file to backup
return 1
fi
date=`date +%Y%m%d-%H%M`
for i in "$@"
do
echo Backed up $i to $i.$date
cp $i $i.$date
done
}
#
# Extract an archive of any type
#
extract(){
if [ $# -lt 1 ]
then
echo Usage: extract file
return 1
fi
if [ -f $1 ] ; then
case $1 in
*.tar.bz2) tar xvjf $1 ;;
*.tar.gz) tar xvzf $1 ;;
*.bz2) bunzip2 $1 ;;
*.rar) unrar x $1 ;;
*.gz) gunzip $1 ;;
*.tar) tar xvf $1 ;;
*.tbz2) tar xvjf $1 ;;
*.tgz) tar xvzf $1 ;;
*.zip) unzip $1 ;;
*.war|*.jar) unzip $1 ;;
*.Z) uncompress $1 ;;
*.7z) 7z x $1 ;;
*) echo "don't know how to extract '$1'..." ;;
esac
else
echo "'$1' is not a valid file!"
fi
}
#
# Creates an archive
#
roll(){
if [ "$#" -ne 0 ] ; then
FILE="$1"
case "$FILE" in
*.tar.bz2|*.tbz2) shift && tar cvjf "$FILE" $* ;;
*.tar.gz|*.tgz) shift && tar cvzf "$FILE" $* ;;
*.tar) shift && tar cvf "$FILE" $* ;;
*.zip) shift && zip "$FILE" $* ;;
*.rar) shift && rar "$FILE" $* ;;
*.7z) shift && 7zr a "$FILE" $* ;;
*) echo "'$1' cannot be rolled via roll()" ;;
esac
else
echo "usage: roll [file] [contents]"
fi
}
#
# XPath
#
xpath(){
if [ $# -ne 2 ]
then
echo Usage: xpath xpath file
return 1
fi
echo "cat $1" | xmllint --shell $2 | sed '/^\/ >/d'
}
#-------------------------------
# Directory Bookmark Functions
#-------------------------------
#
# Add a bookmark, if it doesn't exist
#
bm(){
local val=$(pwd)
for i in ${bookmarks[@]}
do
if [ "$i" == "$val" ]
then
return 1
fi
done
num=${#bookmarks[@]}
bookmarks[$num]=$val
}
#
# Goto specified bookmark
# or previous one by default
#
bcd(){
index=$1
if [ -z $index ]
then
index=$((${#bookmarks[@]}-1))
fi
local val=${bookmarks[$index]}
if [ -z $val ]
then
echo "No such bookmark. Type blist to list bookmarks."
return 1
else
cd "$val"
fi
}
#
# Remove a bookmark
#
brm(){
if [ $# -lt 1 ]
then
echo "Usage: brm <bookmark-index>"
return 1
fi
if [ -z ${bookmarks[$1]} ]
then
echo "No such bookmark"
return 1
fi
bookmarks=(${bookmarks[@]:0:$1} ${bookmarks[@]:$(($1 + 1))})
}
#
# Remove all bookmarks
#
bcl(){
bookmarks=()
}
#
# List all bookmarks
#
bll(){
if [ ${#bookmarks[@]} -ne 0 ]
then
local i=0
while [ $i -lt ${#bookmarks[@]} ]
do
echo $i: ${bookmarks[$i]}
((i++))
done
fi
return 0
}
#-------------------------------
# String manipulation functions
#-------------------------------
#
# substring word start [length]
#
substring(){
if [ $# -lt 2 ]; then
echo "Usage: substring word start [length]"
return 1
fi
if [ -z $3 ]
then
echo ${1:$2}
else
echo ${1:$2:$3}
fi
}
#
# length of string
#
length(){
if [ $# -ne 1 ]; then
echo "Usage: length word"
return 1
fi
echo ${#1}
}
#
# Upper-case
#
upper(){
if [ $# -lt 1 ]; then
echo "Usage: upper word"
return 1
fi
echo ${@^^}
}
#
# Lower-case
#
lower(){
if [ $# -lt 1 ]; then
echo "Usage: lower word"
return 1
fi
echo ${@,,}
}
#
# replace part of string with another
#
replace(){
if [ $# -ne 3 ]; then
echo "Usage: replace string substring replacement"
return 1
fi
echo ${1/$2/$3}
}
#
# replace all parts of a string with another
#
replaceAll(){
if [ $# -ne 3 ]; then
echo "Usage: replace string substring replacement"
return 1
fi
echo ${1//$2/$3}
}
#
# find index of specified string
#
index(){
if [ $# -ne 2 ]; then
echo "Usage: index string substring"
return 1
fi
expr index $1 $2
}
#
# surround string with quotes, for example.
#
surround () {
if [ $# -ne 2 ]
then
echo Usage: surround string surround-with e.g. surround hello \\\"
return 1
fi
echo $1 | sed "s/^/$2/;s/$/$2/" ;
}
If you have any useful functions, please share them in the comments section below.
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