gnu/libexec/uucp/contrib/savelog.sh

#! /bin/sh
# @(#)util/savelog.sh   1.4 26 Oct 1991 22:49:39
#
# savelog - save a log file
#
#    Copyright (C) 1987, 1988 Ronald S. Karr and Landon Curt Noll
#
# See the file COPYING, distributed with smail, for restriction
# and warranty information.
#
# usage: savelog [-m mode] [-u user] [-g group] [-t] [-c cycle] [-l] file...
#
#       -m mode   - chmod log files to mode
#       -u user   - chown log files to user
#       -g group  - chgrp log files to group
#       -c cycle  - save cycle versions of the logfile  (default: 7)
#       -t        - touch file
#       -l        - don't compress any log files        (default: compress)
#       file      - log file names
#
# The savelog command saves and optionally compresses old copies of files
# into an 'dir'/OLD sub-directory.  The 'dir' directory is determined from
# the directory of each 'file'.
#
# Older version of 'file' are named:
#
#               OLD/'file'.<number><compress_suffix>
#
# where <number> is the version number, 0 being the newest.  By default,
# version numbers > 0 are compressed (unless -l prevents it). The
# version number 0 is never compressed on the off chance that a process
# still has 'file' opened for I/O.
#
# If the 'file' does not exist or if it is zero length, no further processing
# is performed.  However if -t was also given, it will be created.
#
# For files that do exist and have lengths greater than zero, the following
# actions are performed.
#
#       1) Version numered files are cycled.  That is version 6 is moved to
#          version 7, version is moved to becomes version 6, ... and finally
#          version 0 is moved to version 1.  Both compressed names and
#          uncompressed names are cycled, regardless of -t.  Missing version
#          files are ignored.
#
#       2) The new OLD/file.1 is compressed and is changed subject to
#          the -m, -u and -g flags.  This step is skipped if the -t flag
#          was given.
#
#       3) The main file is moved to OLD/file.0.
#
#       4) If the -m, -u, -g or -t flags are given, then file is created
#          (as an empty file) subject to the given flags.
#
#       5) The new OLD/file.0 is chanegd subject to the -m, -u and -g flags.
#
# Note: If the OLD sub-directory does not exist, it will be created
#       with mode 0755.
#
# Note: If no -m, -u or -g flag is given, then the primary log file is
#       not created.
#
# Note: Since the version numbers start with 0, version number <cycle>
#       is never formed.  The <cycle> count must be at least 2.
#
# Bugs: If a process is still writing to the file.0 and savelog
#       moved it to file.1 and compresses it, data could be lost.
#       Smail does not have this problem in general because it
#       restats files often.

# common location
PATH="X_UTIL_PATH_X:X_SECURE_PATH_X"; export PATH
COMPRESS="X_COMPRESS_X"
COMP_FLAG="X_COMP_FLAG_X"
DOT_Z="X_DOT_Z_X"
CHOWN="X_CHOWN_X"
GETOPT="X_UTIL_BIN_DIR_X/getopt"

# parse args
exitcode=0      # no problems to far
prog=$0
mode=
user=
group=
touch=
count=7
set -- `$GETOPT m:u:g:c:lt $*`
if [ $# -eq 0 -o  $? -ne 0 ]; then
        echo "usage: $prog [-m mode][-u user][-g group][-t][-c cycle][-l] file ..." 1>&2
        exit 1
fi
for i in $*; do
        case $i in
        -m) mode=$2; shift 2;;
        -u) user=$2; shift 2;;
        -g) group=$2; shift 2;;
        -c) count=$2; shift 2;;
        -t) touch=1; shift;;
        -l) COMPRESS=""; shift;;
        --) shift; break;;
        esac
done
if [ "$count" -lt 2 ]; then
        echo "$prog: count must be at least 2" 1>&2
        exit 2
fi

# cycle thru filenames
while [ $# -gt 0 ]; do

        # get the filename
        filename=$1
        shift

        # catch bogus files
        if [ -b "$filename" -o -c "$filename" -o -d "$filename" ]; then
                echo "$prog: $filename is not a regular file" 1>&2
                exitcode=3
                continue
        fi

        # if not a file or empty, do nothing major
        if [ ! -s $filename ]; then
                # if -t was given and it does not exist, create it
                if [ ! -z "$touch" -a ! -f $filename ]; then
                        touch $filename
                        if [ "$?" -ne 0 ]; then
                                echo "$prog: could not touch $filename" 1>&2
                                exitcode=4
                                continue
                        fi
                        if [ ! -z "$user" ]; then
                                $CHOWN $user $filename
                        fi
                        if [ ! -z "$group" ]; then
                                chgrp $group $filename
                        fi
                        if [ ! -z "$mode" ]; then
                                chmod $mode $filename
                        fi
                fi
                continue
        fi

        # be sure that the savedir exists and is writable
        savedir=`expr "$filename" : '\(.*\)/'`
        if [ -z "$savedir" ]; then
                savedir=./OLD
        else
                savedir=$savedir/OLD
        fi
        if [ ! -s $savedir ]; then
                mkdir $savedir
                if [ "$?" -ne 0 ]; then
                        echo "$prog: could not mkdir $savedir" 1>&2
                        exitcode=5
                        continue
                fi
                chmod 0755 $savedir
        fi
        if [ ! -d $savedir ]; then
                echo "$prog: $savedir is not a directory" 1>&2
                exitcode=6
                continue
        fi
        if [ ! -w $savedir ]; then
                echo "$prog: directory $savedir is not writable" 1>&2
                exitcode=7
                continue
        fi

        # deterine our uncompressed file names
        newname=`expr "$filename" : '.*/\(.*\)'`
        if [ -z "$newname" ]; then
                newname=$savedir/$filename
        else
                newname=$savedir/$newname
        fi

        # cycle the old compressed log files
        cycle=`expr $count - 1`
        rm -f $newname.$cycle $newname.$cycle$DOT_Z
        while [ "$cycle" -gt 1 ]; do
                # --cycle
                oldcycle=$cycle
                cycle=`expr $cycle - 1`
                # cycle log
                if [ -f $newname.$cycle$DOT_Z ]; then
                        mv -f $newname.$cycle$DOT_Z $newname.$oldcycle$DOT_Z
                fi
                if [ -f $newname.$cycle ]; then
                        # file was not compressed for some reason move it anyway
                        mv -f $newname.$cycle $newname.$oldcycle
                fi
        done

        # compress the old uncompressed log if needed
        if [ -f $newname.0 ]; then
                if [ -z "$COMPRESS" ]; then
                        newfile=$newname.1
                        mv $newname.0 $newfile
                else
                        newfile=$newname.1$DOT_Z
                        $COMPRESS $COMP_FLAG < $newname.0 > $newfile
                        rm -f $newname.0
                fi
                if [ ! -z "$user" ]; then
                        $CHOWN $user $newfile
                fi
                if [ ! -z "$group" ]; then
                        chgrp $group $newfile
                fi
                if [ ! -z "$mode" ]; then
                        chmod $mode $newfile
                fi
        fi

        # move the file into the file.0 holding place
        mv -f $filename $newname.0

        # replace file if needed
        if [ ! -z "$touch" -o ! -z "$user" -o \
             ! -z "$group" -o ! -z "$mode" ]; then
                touch $filename
        fi
        if [ ! -z "$user" ]; then
                $CHOWN $user $filename
        fi
        if [ ! -z "$group" ]; then
                chgrp $group $filename
        fi
        if [ ! -z "$mode" ]; then
                chmod $mode $filename
        fi

        # fix the permissions on the holding place file.0 file
        if [ ! -z "$user" ]; then
                $CHOWN $user $newname.0
        fi
        if [ ! -z "$group" ]; then
                chgrp $group $newname.0
        fi
        if [ ! -z "$mode" ]; then
                chmod $mode $newname.0
        fi
done
exit $exitcode