This a really short question. But is there something syntatically wrong with placing a variable $example as an argument for tar in a bash file?
I have the file written as
//only portion that really matters
#!/bin/bash
...
tar -cvpzf $filename $backup_source
//here's the actual code
#!/bin/bash
backup_source="~/momobobo"
backup_dest="~/momobobo_backup/"
dater=`date '+%m-%d-%Y-%H-%M-%S'`
filename="$backup_dest$dater.tgz"
echo “Backing Up your Linux System”
tar -cvpzf $filename $backup_source
echo tar -cvpzf $filename $backup_source
echo “Backup finished”
//and heres the error
“Backing Up your Linux System”
tar: ~/momobobo: Cannot stat: No such file or directory
tar (child): ~/momobobo_backup/07-02-2013-18-34-12.tgz: Cannot open: No such file or directory
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now
tar -cvpzf ~/momobobo_backup/07-02-2013-18-34-12.tgz ~/momobobo
Notice the "echo tar ...". When I copy and paste the output and run it in my terminal there is no problem taring the file. I'm currently running Xubuntu and I already did an update.
~ doesn't expand to your home directory in double quotes.
Just remove the double quotes:
backup_source=~/momobobo
backup_dest=~/momobobo_backup/
In cases where you have things you would want to quote, you can use ~/"momobobo"
How would I go about making a self extracting archive that can be executed on sh?
The closest I have come to is:
extract_archive () {
printf '<archive_contents>' | tar -C "$extract_dir" -xvf -
}
Where <archive_contents> contains a tarball with null characters, %, ' and \ characters escaped and enclosed between single quotes.
Is there any better way to do this so that no escaping is required?
(Please don't point me to shar, makeself etc. I want to write it from scratch.)
Alternative variant is to use marker for end of shell script and use sed to cut-out shell script itself.
Script selfextract.sh:
#!/bin/bash
sed '0,/^#EOF#$/d' $0 | tar zx; exit 0
#EOF#
How to use:
# create sfx
cat selfextract.sh data.tar.gz >example_sfx.sh
# unpack sfx
bash example_sfx.sh
Since shell scripts are not compiled, but executed statement by statement, you can mix binary and text content using a pattern like this (untested):
#!/bin/sh
sed -e '1,/^exit$/d' "$0" | tar -C "${1-.}" -zxvf -
exit
<binary tar gzipped content here>
You can add those two lines to the top of pretty much any tar+gzip file to make it self extractable.
To test:
$ cat header.sh
#!/bin/sh
sed -e '1,/^exit$/d' "$0" | tar -C "${1-.}" -zxvf -
exit
$ tar -czf header.tgz header.sh
$ cat header.sh header.tgz > header.tgz.sh
$ sh header.tgz.sh
header.sh
Some good articles on how to do exactly that could be found at:
http://www.linuxjournal.com/node/1005818.
https://community.linuxmint.com/tutorial/view/1998
Yes, you can do it natively with xtar.
Build xtar elf64 tar self-extractor header (you free to modify it to support elf32, pe and other executable formats), it is based on lightweight bsdtar untar and std elf lib.
cc contrib/xtar.c -o ./xtar
Copy xtar binary to yourTar.xtar
cp ./xtar yourTar.xtar
Append yourTar.tar archive to the end of yourTar.xtar
cat yourTar.tar >> yourTar.xtar
chmod +x yourTar.xtar
I am using make and tar to backup. When executing makefile, tar command shows file changed as we read it. In this case,
the tar package is ok when the warning comes up
but it stops the tar command for the following backup
the file showing the warning in fact doesn't change -- it is really strange that the warning comes up
the files showing the warning come up randomly, I mean, everytime I run my makefile, the files showing the warning are different
--ignore-failed-read doesn't help. I am using tar 1.23 in MinGW
I just changed my computer to WIN7 64 bit. The script works well in old WIN7 32 bit. But the tar version is not as new as the 1.23.
How can I stop the tar's warning to stop my backup following the warning?
Edit-2: it might be the reason
As I said above, the bash shell script worked well in my old computer. Comparing with the old computer, the msys version is different. So is the version of tar command. In the old computer, tar is 1.13.19 and it is 1.23 in the new computer. I copied the old tar command without copying its dependency msys-1.0.dll to the new computer and renamed it tar_old. And I also updated the tar command in the shell script and run the script. Then everything is ok. So, it seemed that the problem is the tar command. I am sure that there is no any file changed when taring. Is it a bug for tar command in new version? I don't know.
Edit-1: add more details
The backup is invoked by a bash shell script. It scans the target directory and builds makefile then invokes make to use tar command for backup. Followed is a typical makefile built by the bash shell script.
#--------------------------------------------
# backup VC
#--------------------------------------------
# the program for packing
PACK_TOOL=tar
# the option for packing tool
PACK_OPTION=cjvf
# M$: C driver
WIN_C_DIR=c:
# M$: D driver
WIN_D_DIR=d:
# M$: where the software is
WIN_PRG_DIR=wuyu/tools
# WIN_PRG_DIR=
# where to save the backup files
BAKDIR=/home/Wu.Y/MS_bak_MSYS
VC_FRAMEWORK=/home/Wu.Y/MS_bak_MSYS/tools/VC/VC_framework.tar.bz2
VC_2010=/home/Wu.Y/MS_bak_MSYS/tools/VC/VC_2010.tar.bz2
.PHONY: all
all: $(VC_FRAMEWORK) $(VC_2010)
$(VC_FRAMEWORK): $(WIN_C_DIR)/$(WIN_PRG_DIR)/VC/Framework/*
#$(PACK_TOOL) $(PACK_OPTION) "$#" --ignore-failed-read /c/$(WIN_PRG_DIR)/VC/Framework
$(VC_2010): $(WIN_C_DIR)/$(WIN_PRG_DIR)/VC/VS2010/*
#$(PACK_TOOL) $(PACK_OPTION) "$#" --ignore-failed-read /c/$(WIN_PRG_DIR)/VC/VS2010
As you can see, the tar package is stored in ~/MS_bak_MSYS/tools/VC/VC_2010.tar.bz2. I run the script in ~/qqaa. ~/MS_bak_MSYS is excluded from tar command. So, the tar file I am creating is not inside a directory I am trying to put into tar file. This is why I felt it strange that the warning came up.
I also encounter the tar messages "changed as we read it". For me these message occurred when I was making tar file of Linux file system in bitbake build environment. This error was sporadic.
For me this was not due to creating tar file from the same directory. I am assuming there is actually some file overwritten or changed during tar file creation.
The message is a warning and it still creates the tar file. We can still suppress these warning message by setting option
--warning=no-file-changed
(http://www.gnu.org/software/tar/manual/html_section/warnings.html
)
Still the exit code return by the tar is "1" in warning message case:
http://www.gnu.org/software/tar/manual/html_section/Synopsis.html
So if we are calling the tar file from some function in scripts, we can handle the exit code something like this:
set +e
tar -czf sample.tar.gz dir1 dir2
exitcode=$?
if [ "$exitcode" != "1" ] && [ "$exitcode" != "0" ]; then
exit $exitcode
fi
set -e
Although its very late but I recently had the same issue.
Issue is because dir . is changing as xyz.tar.gz is created after running the command. There are two solutions:
Solution 1:
tar will not mind if the archive is created in any directory inside .. There can be reasons why can't create the archive outside the work space. Worked around it by creating a temporary directory for putting the archive as:
mkdir artefacts
tar -zcvf artefacts/archive.tar.gz --exclude=./artefacts .
echo $?
0
Solution 2:
This one I like. create the archive file before running tar:
touch archive.tar.gz
tar --exclude=archive.tar.gz -zcvf archive.tar.gz .
echo $?
0
If you want help debugging a problem like this you need to provide the make rule or at least the tar command you invoked. How can we see what's wrong with the command if there's no command to see?
However, 99% of the time an error like this means that you're creating the tar file inside a directory that you're trying to put into the tar file. So, when tar tries to read the directory it finds the tar file as a member of the directory, starts to read it and write it out to the tar file, and so between the time it starts to read the tar file and when it finishes reading the tar file, the tar file has changed.
So for example something like:
tar cf ./foo.tar .
There's no way to "stop" this, because it's not wrong. Just put your tar file somewhere else when you create it, or find another way (using --exclude or whatever) to omit the tar file.
Here is a one-liner for ignoring the tar exit status if it is 1. There is no need to set +e as in sandeep's script. If the tar exit status is 0 or 1, this one-liner will return with exit status 0. Otherwise it will return with exit status 1. This is different from sandeep's script where the original exit status value is preserved if it is different from 1.
tar -czf sample.tar.gz dir1 dir2 || [[ $? -eq 1 ]]
To enhance Fabian's one-liner; let us say that we want to ignore only exit status 1 but to preserve the exit status if it is anything else:
tar -czf sample.tar.gz dir1 dir2 || ( export ret=$?; [[ $ret -eq 1 ]] || exit "$ret" )
This does everything sandeep's script does, on one line.
Simply using an outer directory for the output, solved the problem for me.
sudo tar czf ./../31OCT18.tar.gz ./
Exit codes for tar are restricted, so you don't get to much information.
You can assume that ec=1 is safe to ignore, but it might trip - i.e. the gzip-example in other posts (exit code from external programs).
The reason for the file changed as we read it error/warning can be varying.
A log file inside the directory.
Writing to a tar file in the same directory you are trying to back up.
etc.
Possible workarounds can involve:
exclude known files (log files, tar-files, etc)
ensure log files are written to other directories
This can be quite involved, so you might want to still just run the tar command and preferably safely ignore some errors / warnings.
To do this you will have to:
Save the tar output.
Save the exit code
Check the output against known warnings and errors, not unlike tar's own ignore.
Conditionally pass another exit code to the next program in the pipe.
In OP's case this would have to be wrapped in a script and run as PACK_TOOL.
# List of errors and warnings from "tar" which we will safely ignore.
# Adapt to your findings and needs
IGNORE_ERROR="^tar:.*(Removing leading|socket ignored|file changed as we read it)"
# Save stderr from "tar"
RET=$(tar zcf $BACKUP --exclude Cache --exclude output.log --exclude "*cron*sysout*" $DIR 2>&1)
EC=$? # Save "tar's" exit code
echo "$RET"
if [ $EC -ne 0 ]
then
# Check the RET output, remove (grep -v) any errors / warning you wish to ignore
REAL_ERRORS=$(echo "$RET" | grep "^tar: " | grep -Ev "${IGNORE_ERROR:?}")
# If there is any output left you actually got an error to check
if [ -n "$REAL_ERRORS" ]
then
echo "ERROR during backup of ${DIR:?} to ${BACKUP:?}"
else
echo "OK backup of (warnings ignored) ${DIR:?}"
EC=0
fi
else
echo "OK backup of ${DIR:?}"
fi
It worked for me by adding a simple sleep timeout of 20 sec.
This might happen if your source directory is still writing. Hence put a sleep so that the backup would finish and then tar should work fine. This also helped me in getting the right exit status.
sleep 20
tar -czf ${DB}.${DATE}.tgz ./${DB}.${DATE}
I am not sure does it suit you but I noticed that tar does not fail on changed/deleted files in pipe mode. See what I mean.
Test script:
#!/usr/bin/env bash
set -ex
tar cpf - ./files | aws s3 cp - s3://my-bucket/files.tar
echo $?
Deleting random files manually...
Output:
+ aws s3 cp - s3://my-bucket/files.tar
+ tar cpf - ./files
tar: ./files/default_images: File removed before we read it
tar: ./files: file changed as we read it
+ echo 0
0
Answer should be very simple: Don't save your tar file while "Taring" it in the same directory.
Just do: tar -cvzf resources/docker/php/php.tar.gz .
Eventually,
it will tar the current directory and save it to another directory.
That's easy peasy, lemon squeezy fellas
How can I automate the following with a bash shell script using word designators and word modifiers or something similar?
root#server:/tmp# wget -q http://download.zeromq.org/zeromq-2.2.0.tar.gz
root#server:/tmp# tar -xzf !$:t
tar -xzf zeromq-2.2.0.tar.gz
root#server:/tmp# cd !$:r:r
cd zeromq-2.2.0
root#server:/tmp/zeromq-2.2.0#
When I try something like the below I get errors because word designators and word modifiers don't appear to work the same way in bash scripts as they do in a shell:
Bash Shell Script Example 1:
#!/usr/bin/env bash
wget -q http://download.zeromq.org/zeromq-2.2.0.tar.gz && tar -xzf !$:t && cd !$:r:r
root#server:/tmp# ./install.sh
tar (child): Cannot connect to !$: resolve failed
gzip: stdin: unexpected end of file
tar: Child returned status 128
tar: Error is not recoverable: exiting now
Bash Shell Script Example 2:
#!/usr/bin/env bash
wget -q http://download.zeromq.org/zeromq-2.2.0.tar.gz
tar -xzf !$:t
cd !$:r:r
root#server:/tmp# ./install.sh
tar (child): Cannot connect to !$: resolve failed
gzip: stdin: unexpected end of file
tar: Child returned status 128
tar: Error is not recoverable: exiting now
./install.sh: line 11: cd: !$:r:r: No such file or directory
History substitution works at the command line. In a script, you can use parameter expansion.
#!/usr/bin/env bash
url=http://download.zeromq.org/zeromq-2.2.0.tar.gz
wget -q "$url"
tarfile=${url##*/} # strip off the part before the last slash
tar -xzf "$tarfile"
dir=${tarfile%.tar.gz} # strip off ".tar.gz"
cd "$dir"
If the example provided is the only issue you are trying to resolve perhaps the following can help:
version="2.2.0"
wget -q http://download.zeromq.org/zeromq-${version}.tar.gz
tar -xzf zeromq-${version}.tar.gz
cd zeromq-${version}
In a bash script version could be the first option passed to the script:
version=$1
This does not contain error handling and so on but should get you started.
Actually in my last question I was trying to use the pipe command. I am looking at an example in Process Substitution - Advanced Bash-Scripting Guide.
I tried these lines:
bzip2 -c < pipe > file.tar.bz2 &
tar cf pipe $directory_name
rm pipe
But they are failing with an error:
pipe: No such file or directory.
What's happening here? Is this an error in the ABS guide?
The example you're using appears to assume that the named pipe called "pipe" already exists in the current directory. The "pipe" in here:
bzip2 -c < pipe > file.tar.bz2 &
is not a command name, it is a file name that happens to be a named pipe. Do some reading on "mkfifo" and "named pipes" for more information.