level-0

unix 下tar 执行程序的源代码

#!/bin/sh
#
# Run this script as root on the machine that has the tape drive, to make a
# full dump.
#
# If you give `now' as an argument, the dump is done immediately.
# Otherwise, it waits until 1am, or until the hour given as argument.
# Specify the hour as a number from 0 to 23.
#
# You must edit the file `backup-specs' to set the parameters for your site.

if [ ! -w / ]; then
   echo The backup must be run as root,
   echo or else some files will fail to be dumped.
   exit 1
else
   false
fi

# This is undesirable -- rms.
# rsh albert /usr/local/adm/motd-backup-start

# Get the values of BACKUP_DIRS and BACKUP_FILES, and other variables.
. ./backup-specs

# Maybe sleep until around specified or default hour.
#
if [ "$1" != "now" ]; then
   if [ "$1"x != x ]; then
      spec=$1
   else
      spec=$BACKUP_HOUR
   fi
   pausetime=`date | awk '{hr=substr($4,1,2);\\
      mn=substr($4,4,2);\\
      if((hr+0)<spec)\\
         print 3600*(spec-hr)-60*mn;\\
      else\\
         print 3600*(spec+(24-hr))-60*mn; }' spec=$spec`
   clear
   cat ./dont_touch
   sleep $pausetime
fi

# start doing things

here=`pwd`
LOGFILE=log-`date | awk '{print $2 "-" $3 "-" $6}'`-full
HOST=`hostname | sed 's/\..*//'`
TAR_PART1="/usr/local/bin/tar -c +multi-volume +one-file-system +block=$BLOCKING +sparse"
#TAR_PART1="/usr/local/bin/tar -c +multi-volume +one-file-system +block=$BLOCKING "

# Make sure the log file did not already exist.  Create it.

if [ -f $LOGFILE ] ; then
   echo Log file $LOGFILE already exists.
   exit 1
else
   touch $LOGFILE
fi

mt -f $TAPE_FILE rewind

set $BACKUP_DIRS
while [ $# -ne 0 ] ; do
   host=`echo $1 | sed 's/:.*$//'`
   fs=`echo $1 | sed 's/^.*://'`
   date=`date`
   fsname=`echo $1 | sed 's/\//:/g'`

   TAR_PART2="+listed=/etc/tar-backup/temp.level-0"
   TAR_PART3="+label='Full backup of $fs on $host at $date' -C $fs ."

   echo Backing up $1 at $date | tee -a $LOGFILE

   # Actually back things up.

   if [ $HOST != $host ] ; then
      rsh $host "mkdir /etc/tar-backup 2>&1/dev/null; \
	rm -f /etc/tar-backup/temp.level-0; \
      	$TAR_PART1 -f $HOST:$TAPE_FILE $TAR_PART2 $TAR_PART3" \
	 2>&1 | tee -a $LOGFILE
   else
      mkdir /etc/tar-backup 2>&1/dev/null
      rm -f /etc/tar-backup/temp.level-0
# Using `sh -c exec' causes nested quoting and shell substitution
# to be handled here in the same way rsh handles it.
      sh -c "exec $TAR_PART1 -f $TAPE_FILE $TAR_PART2 $TAR_PART3" 2>&1 | tee -a $LOGFILE
   fi
   if [ $? -ne 0 ] ; then
      echo Backup of $1 failed. | tee -a $LOGFILE
      # I'm assuming that the tar will have written an empty
      # file to the tape, otherwise I should do a cat here.
   else
      if [ $HOST != $host ] ; then
	rsh $host mv -f /etc/tar-backup/temp.level-0 /etc/tar-backup/$fsname.level-0 2>&1 | tee -a $LOGFILE
      else
        mv -f /etc/tar-backup/temp.level-0 /etc/tar-backup/$fsname.level-0 2>&1 | tee -a $LOGFILE
      fi
   fi
   $TAPE_STATUS | tee -a $LOGFILE
   sleep 60
   shift
done

# Dump any individual files requested.

if [ x != "x$BACKUP_FILES" ] ; then
   date=`date`

   TAR_PART2="+listed=/etc/tar-backup/temp.level-0"
   TAR_PART3="+label='Full backup of miscellaneous files at $date'"

   mkdir /etc/tar-backup 2>&1/dev/null
   rm -f /etc/tar-backup/temp.level-0

   echo Backing up miscellaneous files at $date | tee -a $LOGFILE
# Using `sh -c exec' causes nested quoting and shell substitution
# to be handled here in the same way rsh handles it.
   sh -c "exec $TAR_PART1 -f $TAPE_FILE $TAR_PART2 $TAR_PART3 \
    $BACKUP_FILES" 2>&1 | tee -a $LOGFILE
   if [ $? -ne 0 ] ; then
     echo Backup of miscellaneous files failed. | tee -a $LOGFILE
     # I'm assuming that the tar will have written an empty
     # file to the tape, otherwise I should do a cat here.
   else
     mv -f /etc/tar-backup/temp.level-0 /etc/tar-backup/misc.level-0 2>&1 | tee -a $LOGFILE
   fi
   $TAPE_STATUS | tee -a $LOGFILE
else
   echo No miscellaneous files specified | tee -a $LOGFILE
   false
fi

mt -f $TAPE_FILE rewind
mt -f $TAPE_FILE offl

echo Sending the dump log to $ADMINISTRATOR
cat $LOGFILE | sed -f logfile.sed > $LOGFILE.tmp
/usr/ucb/mail -s "Results of backup on `date`" $ADMINISTRATOR < $LOGFILE.tmp

# This is undesirable -- rms.
#rsh albert /usr/local/adm/motd-backup-done &