cp in a script doesnt work with incron?

Question

I created a backup-script for /var/www and /usr/lib/cgi-bin. Every time when a file gets edited or added the script should be called via incron.

root@corkea:~# incrontab -l
/usr/lib/cgi-bin IN_ATTRIB,IN_CREATE,IN_DELETE,IN_CLOSE_WRITE,IN_NO_LOOP create_incremental_backup_of_http_documents_and_cgi.sh
/var/www/html IN_ATTRIB,IN_CREATE,IN_DELETE,IN_CLOSE_WRITE,IN_NO_LOOP create_incremental_backup_of_http_documents_and_cgi.sh

I tested the script in a shell and it works fine, but when using incron the script always returns an error.

The error messages I receive via Mail ..

Apr 27 22:57:49 corkea create_incremental_backup_of_http_documents_and_cgi.sh[15011]: cp: regulÃ€re Datei â/var/tmp/http-documents-and-cgi-of-corkea.gtarâ kann nicht angelegt werden: Die Datei existiert bereits
Apr 27 22:57:49 corkea create_incremental_backup_of_http_documents_and_cgi.sh[15011]: Beende Skript, aufgrund vorheriger Fehler.

Translation:

cp: cant create file /var/tmp/http-documents-and-cgi-of-corkea.gtar, because it exist already.
Stopping script because of previous error(s).

This error only occur when using incron to start the script.

Somehow the script failed at the following if else command ...

if [ -d "${BackupDirectory}/${SubDir}" ]
then
        cp -f "$FileIncremental" "$TmpDir"
else
        mkdir -p "${BackupDirectory}/${SubDir}"
fi

I added && [ -e "$FileIncremental" ] to the if command, but it didnt help neither.

Here is the script...

#!/bin/bash
# Create an incremental GNU-standard backup of Files for the http-Server.
# This script works with Debian Jessie and newer systems.
# Created for my corekea GW 2016-11-27.

MailTo="xxx@web.de"

Source=('/usr/lib/cgi-bin' '/var/www')
BackupDirectory=/media/nas_backups/corkea
TmpDir=/var/tmp

cd /

SubDir="http_documents_and_cgi.d"
FileTimeStamp=$(date "+%Y%m%d%H%M%S")
FileName="http-documents-and-cgi-of-$(uname -n)"
File="${BackupDirectory}/${SubDir}/${FileName}-${FileTimeStamp}.tgz"
FileIncremental="${BackupDirectory}/${SubDir}/${FileName}.gtar"

TimeStamp=$(date "+%F %T")              # This format "2011-12-31 23:59:59" is needed to read the journal
exec 1> >(logger -i -s -t "${0##*/}" -p 3) 2>&1 # all error messages are redirected to syslog journal and after that to stdout
trap "BriefExit" ERR        # Provide information for an admin (via sendmail) when an error occurred and exit the script

function BriefExit(){
    rm -f "$File" "$FileIncremental"
    mv "${TmpDir}/${FileIncremental##*/}" "${BackupDirectory}/${SubDir}" >/dev/null 2>&1
    case "$LANG" in
    de_DE.UTF-8)
        echo "Beende Skript, aufgrund vorheriger Fehler." 1>&2
    ;;
    *)
        echo "Stopping script because of previous error(s)." 1>&2
    ;;
    esac
    MailContent=$(journalctl -p 3 -o "short" --since="$TimeStamp" --no-pager)
    ScriptName="${0##*/}"
    SystemName=$(uname -n)
    MailSubject="${SystemName}: ${ScriptName}"
    printf 'Subject: %s\n\n%s\n' "$MailSubject" "$MailContent" | sendmail "$MailTo"
    exit 1
}

SourceCount="${#Source[@]}"
for ((Index=0;Index<=$SourceCount-1;Index++))
do
    FormatedSource[$Index]="${Source[$Index]#/}"
done

LoopCount=0
OpenFiles=1
while [ "$OpenFiles" -ne 0 ]
do
    if [ "$LoopCount" -le 30 ]
    then
        sleep 1
        OpenFiles=$(lsof "${Source[@]}" | wc -l)
        LoopCount=$((LoopCount + 1))
    else
        case "$LANG" in
        de_DE.UTF-8)
            echo "Es kann keine inkrementelle Sicherheitskopie erstellt werden, weil betroffene Dateien im Schreibemodus sind." 1>&2
        ;;
        *)
            echo "Can't create incremental backup, because some files are open." 1>&2
        ;;
        esac
        BriefExit
    fi
done

if [ -d "${BackupDirectory}/${SubDir}" ] && [ -e "$FileIncremental" ]
then
        cp -f "$FileIncremental" "$TmpDir"
else
        mkdir -p "${BackupDirectory}/${SubDir}"
fi

tar -cpzf "$File" -g "$FileIncremental" "${FormatedSource[@]}"
chmod 0700 "$File"

rm -f "${TmpDir}/${FileIncremental##*/}"

exit 0

What did I wrong and can you help me ?

score 0 · Answer 1 · answered Apr 28 '17 at 12:36

if [ -d "${BackupDirectory}/${SubDir}" ]
then
    cp -f "$FileIncremental" "$TmpDir"
else
    mkdir -p "${BackupDirectory}/${SubDir}"
fi

The commands cp and mkdir used may be an alias or the first found in the PATH. You can add type cp and type mkdir before to add information to output which command is used. You can explicitly specify the path to executable :

/usr/bin/cp
/usr/bin/mkdir

score 0 · Answer 2 · answered Apr 28 '17 at 15:08

0

I found the solution. incron runs my script twice even with IN_NO_LOOP activated. I had to remove IN_ATTRIB and I removed IN_DELETE. Now it works like it should be.

answered Apr 28 '17 at 15:08

Mario

679
6
10

cp in a script doesnt work with incron?

2 Answers2