delperson

Berkely的学生写的

#!/bin/sh 
# Name: delperson 
# Desc: del a person addressbook 
# Args: $1 -> name of person to delete 

# get the helper functions 

. ../ch21/libTYSP.sh 

PATH=/bin:/usr/bin 

# check that a name is given 

if [ $# -lt 1 ] ; then 
    printUSAGE "`basename $0` name" 
    exit 1 
fi 

# check that the address book exists 

MYADDRESSBOOK="./addressbook" 
if [ ! -f "$MYADDRESSBOOK" ] ; then 
    printERROR "$MYADDESSBOOK does not exists, or is not a file." 
    exit 1 
fi 

# initialize the variables holding the location of the temporary files 

TMPF1=/tmp/apupdate.$$ 
TMPF2=/tmp/abdelets.$$ 

# function to clean up temporary files 

doCleanUp() { rm "$TMPF1" "$TMPF1.new" "$TMPF2" 2> /dev/null ; } 

# function to exit if update filed 
Failed() { 
    if [ "$1" -ne 0 ] ; then 
	shift 
	printERROR $@ 
	doCleanUp 
	exit 1 
    fi 
} 

# make a copy of the address book for updating, 
# proceed only if sucessful 

cp "$MYADDRESSBOOK" "$TMPF1" 2> /dev/null 
Failed $? "Could not make a backup of the address book." 

# get a list of all matching lines from the address book copy 
# continue if one or more matches were found 

grep "$1" "$TMPF1" > "$TMPF2" 2> /dev/null 
Failed $? "No matches found." 

# prompt the user for each entry that was found 

exec 5< "$TMPF2" 
while read LINE <&5 
do 

    # display each line formatted 

    echo "$LINE" | awk -F: '{ 
	printf "%-10s %s\n%-10s %s\n%-10s %s\n%-10s %s\n\n",\
	"Name:",$1,"Email:",$2,"Address:",$3,"Phone:",$4 ; 
    }' 

    # prompt for each line, if yes try and remove the line 

    promptYESNO "Delete this entry" "n" 
    if [ "$YESNO" = "y" ] ; then 

	# try to remove the line, store the updated version 
	# in a new file 

	grep -v "$LINE" "$TMPF1" > "$TMPF1.new" 2> /dev/null 
	Failed $? "Unable to update the address book" 

	# replace the old version with the updated version 

	mv "$TMPF1.new" "$TMPF1" 2> /dev/null 
	Failed $? "Unable to update the address book" 

    fi 
done 
exec 5<&- 

# save the original version 

mv "$MYADDRESSBOOK" "$MYADDRESSBOOK".bak 2> /dev/null 
Failed $? "Unable to update the address book" 

# replace the original with the edited version 

mv "$TMPF1" "$MYADDRESSBOOK" 2> /dev/null 
Failed $? "Unable to update the address book" 

# clean up 

doCleanUp 

exit $?