compare_dir.sh

#!/bin/bash
if [ -z "$2" ];then
	echo "Usage: $(basename $0) <DIR1> <DIR2>"
	echo "       $(basename $0) /home/exercise/src /home/exercise/dst"
	exit 1
fi

DIR1=$1
DIR2=$2

( cd "$DIR1"; find . ) > /tmp/dir1 
( cd "$DIR2"; find . ) > /tmp/dir2 

#diff -u /tmp/dir1 /tmp/dir2
diff --old-group-format='%<' \
     --new-group-format='%>' \
     --unchanged-group-format='' \
     --changed-group-format='%<%>' \
     --old-line-format='SRC: %L' \
     --new-line-format='DST: %L' \
     /tmp/dir1 /tmp/dir2

compare_dir1.sh

#!/bin/bash
if [ -z "$2" ];then
	echo "Usage: $(basename $0) <DIR1> <DIR2>"
	echo "       $(basename $0) /home/exercise/src /home/exercise/dst"
	exit 1
fi

DIR1=$1
DIR2=$2

#diff -u /tmp/dir1 /tmp/dir2
diff --old-group-format='%<' \
     --new-group-format='%>' \
     --unchanged-group-format='' \
     --changed-group-format='%<%>' \
     --old-line-format='SRC: %L' \
     --new-line-format='DST: %L' \
     <(cd "$DIR1"; find .) <(cd "$DIR2"; find .)

compare_dir2.sh

#!/bin/bash
if [ -z "$2" ];then
	echo "Usage: $(basename $0) <DIR1> <DIR2>"
	echo "       $(basename $0) /home/exercise/src /home/exercise/dst"
	exit 1
fi

DIR1=$1
DIR2=$2

#diff -u /tmp/dir1 /tmp/dir2
echo "--- $DIR1 only ---"
diff --old-group-format='%<' \
     --new-group-format='' \
     --unchanged-group-format='' \
     --changed-group-format='%<' \
     --old-line-format='%L' \
     <(cd "$DIR1"; find .) <(cd "$DIR2"; find .) | sed -e "s/^.//" | awk "{printf \"%s%s\n\", \"$DIR1\", \$0}"

echo "--- $DIR2 only ---"
diff --old-group-format='' \
     --new-group-format='%>' \
     --unchanged-group-format='' \
     --changed-group-format='%>' \
     --new-line-format='%L' \
     <(cd "$DIR1"; find .) <(cd "$DIR2"; find .) | sed -e "s/^.//" | awk "{printf \"%s%s\n\", \"$DIR2\", \$0}"

http_request.sh

#!/bin/bash
#
# HTTP request without external programs
#
HOSTNAME=www.naver.com
URL='/'

# 1. open tcp
exec 3<>/dev/tcp/${HOSTNAME}/80 

# 2. send request
# IMPORTANT "Connection: close"
CR=$'\x0d'

REQUEST="GET ${URL} HTTP/1.1${CR}
Host: ${HOSTNAME}${CR}
Connection: close${CR}
User-Agent: bash${CR}
Accept: */*${CR}
${CR}
"
# double quote preserves \n
1>&3 echo "$REQUEST"

# using cat
if false;then
	<<-EOF 1>&3 cat 
	GET ${URL} HTTP/1.1${CR}
	Host: ${HOSTNAME}${CR}
	Connection: close${CR}
	User-Agent: bash${CR}
	Accept: */*${CR}
	${CR}
	EOF
fi

# 3. receive response
#<&3 cat 
#while read line;do echo "$line";done <&3
while read -u 3 line;do echo "$line";done 2>/dev/null