I need help with replacing the following script with a different format where a configuration file, and a loop is used.
[FedoraC]$ cat script.sh
#!/bin/bash
grep -q /tmp /etc/fstab
if [ $? -eq 0 ]; then
echo "True"
else
echo "False"
fi
mount | grep ' /tmp' | grep nodev
if [ $? -eq 0 ]; then
echo "True"
else
echo "False"
fi
mount | grep /tmp | grep nosuid
if [ $? -eq 0 ]; then
echo "True"
else
echo "False"
fi
So far I have the following script which should take the values from a source/conf file and run each command found in the conf file one by one. After the command is executed the output would be "True" or "False"
conf file is formed by Unix commands: /opt/conf1
[FedoraC]$ cat conf1
grep -q /tmp /etc/fstab
mount | grep /tmp | grep nodev
mount | grep /tmp | grep nosuid
mount | grep /tmp | grep noexec
[FedoraC]$ cat new_script.sh
#!/bin/bash
. conf1
for i in $#;
do $i
if [ $i -eq 0 ]; then
echo "Passed"
else
echo "Failed"
fi
done
Instead of displaying the output based on the conditional statement, the script runs each line one by one from conf1, and not echo messages are seen.
Can I get some help please.
try this:
#! bin/bash
while read L; do
echo $L'; exit $?'|sh
if [ $? -eq 0 ]; then
echo Pass
else
echo Failed
fi
done < conf1
The more robust and canonical way to do this would be to have a directory /opt/conf1.d/, and put each of your lines as an executable script in this directory. You can then do
for file in /opt/conf1.d/*
do
[[ -x $file ]] || continue
if "$file"
then
echo "Passed"
else
echo "Failed"
fi
done
This has the advantages of supporting multi-line scripts, or scripts with more complex logic. It also lets you write the check script in any language, and lets scripts and packages add and remove contents easily and non-interactively.
If you really want to stick with your design, you can do it with:
while IFS= read -r line
do
if ( eval "$line" )
then
echo "Passed"
else
echo "Failed"
fi
done < /opt/conf1
The parentheses in the if statement runs eval in a subshell, so that lines can't interfere with each other by setting variables or exiting your entire loop.
Related
I am writing a bash script to iterate in directory and sub-directories, check if a file opened by a process,
if yes move it to another location
if no skip it
My issue is that the Source folders have Spaces is their names such as "FTP SYNC LOCAL"
my script is able so far to iterate in the folders and subfolders and test if a file is opened by another process.
It only does this if the file name doesn't contain a SPACE in its name, if it does, nothing happened
print_folder_recurse() {
for i in "$1"/* ;do
if [ -d "$i" ];then
echo $i
#lsof "$i" | grep Serv-U | wc -l
print_folder_recurse "$i"
elif [ -f "$i" ]; then
echo $i
flag=$(lsof "$i" | grep Serv-U | wc -l)
if [ $flag == 0 ];then
echo "Done"
elif [ $flag != 0 ];then
echo "Skip Next"
fi
fi
done
}
path=""
if [ -d "$1" ]; then
path=$1;
else
direct="/Source/FTP Sync"
echo $direct
path="$direct"
fi
#echo "base path: $path"
print_folder_recurse $path
The problem is at the bottom of the code with the variable "direct". If I write it
direct="/Source"
echo $direct
path="$direct"
fi
#echo "base path: $path"
print_folder_recurse $path
The file execute.
I can prevent the issue by writing the folder Source/FTP_Sync but I can do this since it will affect a major workflow.
Any help will be apprecaited
the print_folder_recurse functions reads the $path variable as 2 seperate arguments because of the space in between the variable i.e $1 = /Source/Ftp while $2 = Sync. The solution is to wrap the $path variable in double quote like this print_folder_recurse "$path"so that print_folder_recurse can read it as a single argument
I'm writing a bash script that goes through a for loop which is a list of each hostname, then will test each one if it's responding on port 22, if it is then execute an ssh session, however both the first and second if statements are only executed on the first host in the list, not the rest of the hosts. If the host isn't responding on port 22, I want the script to continue to the next host. Any ideas how to ensure the script runs the ssh on each host in the list? Should this be another for loop?
#!/bin/bash
hostlist=$(cat '/local/bin/bondcheck/hostlist_test.txt')
for host in $hostlist; do
test=$(nmap $host -P0 -p 22 | egrep 'open|closed|filtered' | awk '{print $2}')
if [[ $test = 'open' ]]; then
cd /local/bin/bondcheck/
mv active.current active.fixed
ssh -n $host echo -n "$host: ; cat /proc/net/bonding/bond0 | grep Active" >> active.current
result=$(comm -13 active.fixed active.current)
if [ "$result" == "" ]; then
exit 0
else
echo "$result" | cat -n
fi
else
echo "$host is not responding"
fi
done
exit 0 exits the entire script; you just want to move on to the next iteration of the loop. Use continue instead.
You problem is most likely in the lines
if [ "$result" == "" ]
then
exit 0
else
echo "$result" | cat -n
fi
Here the exit 0 causes the entire script to exit when the $result is empty. You could the way around using :
if [ "$result" != "" ] #proceeding on non-empty 'result'
then
echo "$result" | cat -n
fi
I wrote a little bash script called "wp", which upload files to an ftp server. It uses the wput utility. It takes the list of files from a text file. When uploading is ready it comments out the line with a double cross in the text file. The success of the upload is detected according to the last line in the logfile. My question is how can I avoid multiple starting of my script? I am trying to detect with pgrep if the instance is running, but doesn't work correctly:
#!/bin/bash
if [ "$(pgrep ^wp$|wc -l)" -eq "2" ]
then
echo "$(pgrep ^wp$)"
echo "$(pgrep ^wp$|wc -l)"
echo "wp script is starting..."
else
echo "$(pgrep ^wp$)"
echo "$(pgrep ^wp$|wc -l)"
echo "wp script is already running!"
exit
fi
server="ftp://username:password#ftp.ftpserver.com"
logfile=~/uploads.log
listfile=~/uploads.txt
list_backup=~/uploads_bak000.txt
while read f;
do
ret=""
if [ "${f:0:1}" = "#" -o "$f"1 = 1 ]
then
if [ "$f"1 = 1 ]
then
:
#echo "invalid string: "$f
else
#first character is remark sign # then empty command -> :
echo "remark line skipped: "$f
fi
else
#while string $ret is empty
while [ -z "$ret" ]
do
wput "$f" --tries=-1 "$server" 2>&1|tee -a $logfile #> /dev/null
ret=$(tail -n 1 "$logfile"|grep "FINISHED\|Nothing\|Skipped\|Transfered")
done
if [ -n "$ret" ]
then
cat $listfile > $list_backup
awk -v f="$f" '{if ($0==f && $0!~/#/) print "#" $0; else print $0;}' $list_backup > $listfile
fi
fi
done < $listfile
There are quick-n-dirty solutions that use ps with grep (don't do this).
It is better to use a lock file as a "mutex". A nice way of doing this is by using a directory as a lock file (http://mywiki.wooledge.org/BashFAQ/045).
I would also suggest taking a look at:
http://mywiki.wooledge.org/ProcessManagement#How_do_I_make_sure_only_one_copy_of_my_script_can_run_at_a_time.3F
, which mentions use of setlock(http://cr.yp.to/daemontools/setlock.html) that abstracts the lock file handling for you.
How can I use the test command for an arbitrary number of files, passed in using an argument with a wildcard?
For example:
test -f /var/log/apache2/access.log.* && echo "exists one or more files"
Currently, it prints
error: bash: test: too many arguments
This solution seems to me more intuitive:
if [ `ls -1 /var/log/apache2/access.log.* 2>/dev/null | wc -l ` -gt 0 ];
then
echo "ok"
else
echo "ko"
fi
To avoid "too many arguments error", you need xargs. Unfortunately, test -f doesn't support multiple files. The following one-liner should work:
for i in /var/log/apache2/access.log.*; do test -f "$i" && echo "exists one or more files" && break; done
By the way, /var/log/apache2/access.log.* is called shell-globbing, not regexp. Please see Confusion with shell-globbing wildcards and Regex for more information.
First, store files in the directory as an array:
logfiles=(/var/log/apache2/access.log.*)
Then perform a test on the count of the array:
if [[ ${#logfiles[#]} -gt 0 ]]; then
echo 'At least one file found'
fi
This one is suitable for use with the Unofficial Bash Strict Mode, no has non-zero exit status when no files are found.
The array logfiles=(/var/log/apache2/access.log.*) will always contain at least the unexpanded glob, so one can simply test for existence of the first element:
logfiles=(/var/log/apache2/access.log.*)
if [[ -f ${logfiles[0]} ]]
then
echo 'At least one file found'
else
echo 'No file found'
fi
If you wanted a list of files to process as a batch, as opposed to doing a separate action for each file, you could use find, store the results in a variable, and then check if the variable was not empty. For example, I use the following to compile all the .java files in a source directory.
SRC=`find src -name "*.java"`
if [ ! -z $SRC ]; then
javac -classpath $CLASSPATH -d obj $SRC
# stop if compilation fails
if [ $? != 0 ]; then exit; fi
fi
You just need to test if ls has something to list:
ls /var/log/apache2/access.log.* >/dev/null 2>&1 && echo "exists one or more files"
Variation on a theme:
if ls /var/log/apache2/access.log.* >/dev/null 2>&1
then
echo 'At least one file found'
else
echo 'No file found'
fi
ls -1 /var/log/apache2/access.log.* | grep . && echo "One or more files exist."
Or using find
if [ $(find /var/log/apache2/ -type f -name "access.log.*" | wc -l) -gt 0 ]; then
echo "ok"
else
echo "ko"
fi
This condition below doesn't produce stderr. the condition's blackhole (/dev/null) doesn't prevent the stderr in cmd.
if [[ $(ls -1 /var/log/apache2/access.log.* | wc -l ) -gt 0 ]] 2> /dev/null
therefore I suggests this code.
if [[ $(ls -1 /var/log/apache2/access.log.* | wc -l ) -gt 0 ]] 2> /dev/null
then
echo "exists one or more files."
fi
more simplyfied:
if ls /var/log/apache2/access.log.* 2>/dev/null 1>&2; then
echo "ok"
else
echo "ko"
fi
A little history behind this - I'm trying to write a nagios plugin to detect if an nfs mount is unmounted and if a mount is stale, which is where I'm running into a problem.
What I'm trying to achieve is detecting if a mount is stale. The problem I'm trying to work around is the fact that a stale nfs handle causes any action on that directory to hang and timeout after 3-4 minutes. By forcing a timeout onto a stat command inside an nfs mounted directory with read, I should be able to work around that problem.
So I picked up this snippet somewhere, which works perfectly when run manually from the cli on an nfs client (where /www/logs/foo is a stale nfs mount)
$ read -t 2 < <(stat -t /www/logs/foo/*); echo $?
1
The problem comes when I try to incorporate this snippet into a script like so (snippet attached, full script attached at the end):
list_of_mounts=$(grep nfs /etc/fstab | grep -v ^# | awk '{print $2'} | xargs)
exitstatus $LINENO
for X in $list_of_mounts; do
AM_I_EXCLUDED=`echo " $* " | grep " $X " -q; echo $?`
if [ "$AM_I_EXCLUDED" -eq "0" ]; then
echo "" >> /dev/null
#check to see if mount is mounted according to /proc/mounts
elif [ ! `grep --quiet "$X " /proc/mounts; echo $?` -eq 0 ]; then
#mount is not mounted at all, add to list to remount
remount_list=`echo $remount_list $X`;
#now make sure its not stale
elif [ ! "`read -t 2 < <(stat -t $X/*) ; echo $?`" -eq "0" ]; then
stalemount_list=`echo $stalemount_list $X`
fi
Gives me this error:
/usr/lib64/nagios/plugins/check_nfs_mounts.sh: command substitution: line 46: syntax error near unexpected token `<'
/usr/lib64/nagios/plugins/check_nfs_mounts.sh: command substitution: line 46: `read -t 2 < <( '
/usr/lib64/nagios/plugins/check_nfs_mounts.sh: command substitution: line 46: syntax error near unexpected token `)'
/usr/lib64/nagios/plugins/check_nfs_mounts.sh: command substitution: line 46: ` ) ; echo $?'
/usr/lib64/nagios/plugins/check_nfs_mounts.sh: line 46: [: stat -t /www/logs/foo/*: integer expression expected
I was able to work around the syntax error by using " read -t 2<<< $(stat -t $X/)" instead of " read -t 2< <(stat -t $X/)", however stat no longer benefits from the timeout on read, which takes me back to the original problem.
While I'm open to new solutions, I'm also curious as to what behavior might be causing this shell vs script difference.
Full nagios check:
#!/bin/bash
usage() {
echo "
Usage:
check_nfs_mounts.sh
It just works.
Optional: include an argument to exclude that mount point
"
}
ok() {
echo "OK - $*"; exit 0
exit
}
warning() {
echo "WARNING - $*"; exit 1
exit
}
critical() {
echo "CRITICAL - $*"; exit 2
exit
}
unknown() {
echo "UNKNOWN - $*"; exit 3
exit
}
exitstatus() {
if [ ! "$?" -eq "0" ] ;
then unknown "Plugin failure - exit code not OK - error line $*"
fi
}
# Get Mounts
list_of_mounts=$(grep nfs /etc/fstab | grep -v ^# | awk '{print $2'} | xargs)
exitstatus $LINENO
for X in $list_of_mounts; do
AM_I_EXCLUDED=`echo " $* " | grep " $X " -q; echo $?`
if [ "$AM_I_EXCLUDED" -eq "0" ]; then
echo "" >> /dev/null
#check to see if mount is mounted according to /proc/mounts
elif [ ! `grep --quiet "$X " /proc/mounts; echo $?` -eq 0 ]; then
#mount is not mounted at all, add to list to remount
remount_list=`echo $remount_list $X`;
#now make sure its not stale
elif [ ! "`read -t 2 <<< $(stat -t $X/*) ; echo $?`" -eq "0" ]; then
stalemount_list=`echo $stalemount_list $X`
fi
done
#Make sure result is a number
if [ -n "$remount_list" ] && [ -n "$stalemount_list" ]; then
critical "Not mounted: $remount_list , Stale mounts: $stalemount_list"
elif [ -n "$remount_list" ] && [ -z "$stalemount_list"]; then
critical "Not mounted: $remount_list"
elif [ -n "$stalemount_list" ] && [ -n "$remount_list" ]; then
critical "Stale mount: $stalemount_list"
elif [ -z "$stalemount_list" ] && [ -z "$remount_list" ]; then
ok "All mounts mounted"
fi
You need to make sure your shebang specifies Bash:
#!/bin/bash
The reason for the error message is that on your system, Bash is symlinked to /bin/sh which is used when there's no shebang or when it's #!/bin/sh.
In this case, Bash is run as if you had started it with bash --posix which disables some non-POSIX features such as process substitution (<()), but confusingly not others such as here strings (<<<).
Change your shebang and you should be OK.
You can save the output of a subshell in this way:
$ read a < <(echo one)
$ echo $a
one
Or in this way (if you just want to process $a and forget it:
$ ( echo one; echo two) | (read a; echo $a)
one
The first variant will work only in bash. Bourne Shell (/bin/sh) does not support this syntax. May be that is the reason why you get the error message. May be you script is interpreted by /bin/sh not by /bin/bash