I have the following in script.tcl:
#!/usr/bin/env tclsh
set disk(free) [exec -- stat -f -c 'scale=3;(%a*%S)/1024/1024/1024' / | bc ]
When I execute the script, I get the following output: (translated from Hungarian)
stat: missing operand
For more information execute the „stat --help” command.
while executing
"exec -- stat -f -c 'scale=3"
invoked from within
"set disk(free) [exec -- stat -f -c 'scale=3;(%a*%S)/1024/1024/1024' / | bc ]"
(file "~/script.tcl" line 2)
What am I doing wrong? Running the command on it's own works just fine.
You have to brace your expressions instead of single quotes.
% exec stat -f -c {scale=3;(%a*%S)/1024/1024/1024} / | bc
137.916
%
Related
I want to use a bash script to output the contents of top command and then write it to a json file. But I'm having difficulty writing the slashes/encodings/line breaks into a file with a valid json object
Here's what I tried:
#!/bin/bash
message1=$(top -n 1 -o %CPU)
message2=$(top -n 1 -o %CPU | jq -aRs .)
message3=$(top -n 1 -o %CPU | jq -Rs .)
message4=${message1//\\/\\\\/}
echo "{\"message\":\"${message2}\"}" > file.json
But when I look at the file.json, it looks soemthing like this:
{"message":""\u001b[?1h\u001b=\u001b[?25l\u001b[H\u001b[2J\u001b(B\u001b[mtop - 21:34:53 up 55 days, 5:14, 2 users, load average: 0.17, 0.09, 0.03\u001b(B\u001b[m\u001b[39;49m\u001b(B\u001b[m\u001b[39;49m\u001b[K\nTasks:\u001b(B\u001b[m\u001b[39;49m\u001b[1m 129 \u001b(B\u001b[m\u001b[39;49mtotal,\u001b(B\u001b[m\u001b[39;49m\u001b[1m 1 \u001b(B\u001b[m\u001b[39;49mrunning,\u001b(B\u001b[m\u001b[39;49m\u001b[1m 128 \u001b(B\u001b[m\u001b[39;49msleeping,\u001b(B\u001b[m
Each of the other attempts with message1 to message4 all result in various json syntax issues.
Can anyone suggest what I should try next?
You don't need all the whistle of echo and multiple jq invocations:
top -b -n 1 -o %CPU | jq -aRs '{"message": .}' >file.json
Or pass the output of the top command as an argument variable.
Using --arg to pass arguments to jq:
jq -an --arg msg "$(top -b -n 1 -o %CPU)" '{"message": $msg}' >file.json
I am trying to write a message to an existing file.
The check is performed to see certain variable values and then append a message accordingly to file, but $data value is not written to a file.
Please let me know is something wrong with my code?
proc run_sanity {} {
global rundir typep corner_name reflib compLib
cd $rundir
set filename "sanity.txt"
set fileId [open $filename "w"]
if {[file exists $filename]} {
exec rm -rf $rundir/sanity.txt
}
exec grep operating_conditions -A 3 $compLib | grep -v default | grep -v lu | grep -v variable > $rundir/sanity.txt
exec grep nom $compLib >> $rundir/sanity.txt
exec grep library $compLib | grep -v slew | grep -v features >> $rundir/sanity.txt
set driver [exec grep -c driver_waveform $compLib]
set recovery [exec grep -c recovery $compLib]
set removal [exec grep -c removal $compLib]
if {$driver > 0 && $recovery > 0 && $removal > 0} {
set data "No data found for Driver waveform, Recovery and Removal Table.\n"
puts $fileId $data
} else {
set data "Driver waveform, Recovery and Removal table is present in .lib.\n"
puts $fileId $data
}
close $fileId
exec emacs $rundir/sanity.txt &
}
Thanks
Dan
Basically, your code is
set fileId [open $filename "w"] ; 1
if {[file exists $filename]} { ; 2
exec rm -rf $rundir/sanity.txt ; 3
}
puts $fileId $data ; 4
So,
You open the file for writing.
The "w" mode makes sure the file is created if it does not exist
or is truncated if it does.
You then check if the file exists.
This check always passes because of the first step
(and unless you have a race on your filesystem—with some other
process deleting the file before this check happens).
You delete the file.
Since this supposedly happens on a filesystem with POSIX semantics
(that is, on some Unix-y OS), any file descriptor opened to that
deleted file counts as a live reference to that file, so while the file
entry is removed from its directory on the file system its data is not,
and reading and writing of this data happens just OK—it's just
inaccessible outside of your process because this data no more has any
name on the filesystem.
By the way, this trick is routinely used by Unix software to keep
temporary data: a file is created and then immediately removed from
the file system while keeping an open file descriptor to it.
You write to the file. Writing happens OK and the data is actually
stored on the file system.
Once you close your file, its data loses the last live reference to it
and so at that very moment that data gets deleted.
So you should supposedly reconsider your approach to managing this file.
So far, there's little sanity in handling "sanity.txt". ;-)
By the way, why do you use rm -rf (and why -r?) instead of just file delete right from Tcl? That would be a tad faster.
This code works as i moved the fileId inside the if loop, taking care of POSIX semantics.
proc run_sanity {} {
global rundir typep corner_name reflib compLib
cd $rundir
set Sname "sanity.txt"
##set fileId [open $filename "a"]
if {[file exists $Sname]} {
file delete $rundir/sanity.txt
}
after 10000 {destroy .dialog4}
tk_dialog .dialog4 "Running Sanity:" "SANITY TEST RUNNING" info 0 OK
exec grep operating_conditions -A 3 $compLib | grep -v default | grep -v lu | grep -v variable > $rundir/sanity.txt
exec grep nom $compLib >> $rundir/sanity.txt
exec echo "" >> $rundir/sanity.txt
exec grep library $compLib | grep -v slew | grep -v features >> $rundir/sanity.txt
exec echo "" >> $rundir/sanity.txt
set driver [exec grep -c driver_waveform $compLib]
set recovery [exec grep -c recovery $compLib]
set removal [exec grep -c removal $compLib]
cd $rundir
if {$driver > 0 && $recovery > 0 && $removal > 0} {
set filename "sanity.txt"
set fileId [open $filename "a"]
set msg "Driver waveform, Recovery and Removal table is present in .lib.\n"
puts $fileId $msg
close $fileId
} else {
set filename "sanity.txt"
set fileId [open $filename "a"]
set msg "No data found for Driver waveform, Recovery and Removal Table.\n"
puts $fileId $msg
close $fileId
}
exec emacs $rundir/sanity.txt &
}
I'm a command line newbie and I'm trying to figure out how I can add a header to multiple .csv files. The new header should have the following: 'TaxID' and 'filename'
I've tried multiple commands like sed, ed, awk, echo but if it worked it only changed the first file it found (I said *.csv in my command) and I can only manage this for TaxID.
Can anyone help me to get the filename into the header as well and do this for all my csv files?
(Note, I'm using a Mac)
Thank you!
Here's one way to do it, there are certainly others:
$ for i in *.csv;do echo $i;cp "$i" "$i.bak" && { echo "TaxID,$i"; cat "$i.bak"; } >"$i";done
Here's a sample run:
$ cat file1.csv
1,2
3,4
$ cat file2.csv
a,b
c,d
$ for i in *.csv;do echo $i;cp "$i" "$i.bak" && { echo "TaxID,$i"; cat "$i.bak"; } >"$i";done
file1.csv
file2.csv
$ cat file1.csv.bak
1,2
3,4
$ cat file1.csv
TaxID,file1.csv
1,2
3,4
$ cat file2.csv.bak
a,b
c,d
$ cat file2.csv
TaxID,file2.csv
a,b
c,d
Breaking it down:
$ for i in *.csv; do
This loops over all the files ending in .csv in the current directory. Each will be put in the shell variable i in turn.
echo $i;
This just echoes the current filename so you can see the progress. This can be safely left out.
cp "$i" "$i.bak"
Copy the current file (whose name is in i) to a backup. This is both to preserve the file if something goes awry, and gives subsequent commands something to copy from.
&&
Only run the subsequent commands if the cp succeeds. If you can't make a backup, don't continue.
{
Start a group command.
echo "TaxID,$i";
Output the desired header.
cat "$i.bak";
Output the original file.
}
End the group command.
>"$i";
Redirect the output of the group command (the new header and the contents of the original file) to the original file. This completes one file.
done
Finish the loop over all the files.
For fun, here are a couple of other ways (one JRD beat me to), including one using ed!
$ for i in *.csv;do echo $i;perl -p -i.bak -e 'print "TaxID,$ARGV\n" if $. == 1' "$i";done
$ for i in *.csv;do echo $i;echo -e "1i\nTaxID,$i\n.\nw\nq\n" | ed "$i";done
Here is on way in perl that modifies the files in place by adding a header of TaxID,{filename}, ignoring adding the header if it thinks it already exists.
ls
a.csv b.csv
cat a.csv
1,a.txt
2,b.txt
cat b.csv
3,c.txt
4,d.txt
ls *.csv | xargs -I{} -n 1 \
perl -p -i -e 'print "TaxID,{}\n" if !m#^TaxID# && !$h; $h = 1;' {}
cat a.csv
TaxID,a.csv
1,a.txt
2,b.txt
cat b.csv
TaxID,b.csv
3,c.txt
4,d.txt
You may want to create some backups of your files, or run on a few sample copies before running in earnest.
Explanatory:
List all files in directory with .csv extenstion
ls *.csv
"Pipe" the output of ls command into xargs so the perl command can run for each file. -I{} allows the filename to be subsequently referenced with {}. -n tells xargs to only pass 1 file at a time to perl.
| xargs -I{} -n 1
-p print each line of the input (file)
-i modifying the file in place
-e execute the following code
perl -p -i -e
Perl will implicitly loop over each line of the file and print it (due to -p). Print the header if we have not printed the header already and the current line doesn't already look like a header.
'print "TaxID,{}\n" if !m#^TaxID# && !$h; $h = 1;'
This is replaced with the filename.
{}
All told, in this example the commands to be run would be:
perl -p -i -e 'print "TaxID,{}\n" if !m#^TaxID# && !$h; $h = 1;' a.csv
perl -p -i -e 'print "TaxID,{}\n" if !m#^TaxID# && !$h; $h = 1;' b.csv
perl -p -i -e 'print "TaxID,{}\n" if !m#^TaxID# && !$h; $h = 1;' c.csv
perl -p -i -e 'print "TaxID,{}\n" if !m#^TaxID# && !$h; $h = 1;' d.csv
I am trying to catch the log, Serverlist.txt contains some servers details like root 10.0.0.1 22 TestServer, while I run the script it only read the first line and exit, its not working for further lines. Below is my script.
newdate1=`date -d "yesterday" '+%b %d' | sed 's/0/ /g'`
newdate2=`date -d "yesterday" '+%d/%b/%Y'`
newdate3=`date -d "yesterday" '+%y%m%d'`
DL=/opt/$newdate3
Serverlist=/opt/Serverlist.txt
serverlog()
{
mkdir -p $DL/$NAME
ssh -p$PORT $USER#$IP "cat /var/log/messages*|grep '$newdate1'"|cat > $DL/$NAME/messages.log
}
while read USER IP PORT NAME
do
serverlog
sleep 1;
done <<<"$Serverlist"
Use < instead of <<<. <<<is a Here String substitution. The right side is evaluated, and then the result is read from the loop as standard input:
$ FILE="my_file"
$ cat $FILE
First line
Last line
$ while read LINE; do echo $LINE; done <$FILE
First line
Last line
$ set -x
$ while read LINE; do echo $LINE; done <<<$FILE
+ read LINE
+ echo my_file
my_file
+ read LINE
$ while read LINE; do echo $LINE; done <<<$(ls /home)
++ ls /home
+ read LINE
+ echo antxon install lost+found
antxon install lost+found
+ read LINE
$
I got the answer from another link.
you can use "-n" option in ssh, this will not break the loop and you will get the desired result.
I am working with bash shell script. I need to execute an URL using shell script and then parse the json data coming from it.
This is my URL - http://localhost:8080/test_beat and the responses I can get after hitting the URL will be from either these two -
{"error": "error_message"}
{"success": "success_message"}
Below is my shell script which executes the URL using wget.
#!/bin/bash
DATA=$(wget -O - -q -t 1 http://localhost:8080/test_beat)
#grep $DATA for error and success key
Now I am not sure how to parse json response in $DATA and see whether the key is success or error. If the key is success, then I will print a message "success" and print $DATA value and exit out of the shell script with zero status code but if the key is error, then I will print "error" and print $DATA value and exit out of the shell script with non zero status code.
How can I parse json response and extract the key from it in shell script?
I don't want to install any library to do this since my JSON response is fixed and it will always be same as shown above so any simpler way is fine.
Update:-
Below is my final shell script -
#!/bin/bash
DATA=$(wget -O - -q -t 1 http://localhost:8080/tester)
echo $DATA
#grep $DATA for error and success key
IFS=\" read __ KEY __ MESSAGE __ <<< "$DATA"
case "$KEY" in
success)
exit 0
;;
error)
exit 1
;;
esac
Does this looks right?
If you are going to be using any more complicated json from the shell and you can install additional software, jq is going to be your friend.
So, for example, if you want to just extract the error message if present, then you can do this:
$ echo '{"error": "Some Error"}' | jq ".error"
"Some Error"
If you try this on the success case, it will do:
$echo '{"success": "Yay"}' | jq ".error"
null
The main advantage of the tool is simply that it fully understands json. So, no need for concern over corner cases and whatnot.
#!/bin/bash
IFS= read -d '' DATA < temp.txt ## Imitates your DATA=$(wget ...). Just replace it.
while IFS=\" read -ra LINE; do
case "${LINE[1]}" in
error)
# ERROR_MSG=${LINE[3]}
printf -v ERROR_MSG '%b' "${LINE[3]}"
;;
success)
# SUCCESS_MSG=${LINE[3]}
printf -v SUCCESS_MSG '%b' "${LINE[3]}"
;;
esac
done <<< "$DATA"
echo "$ERROR_MSG|$SUCCESS_MSG" ## Shows: error_message|success_message
* %b expands backslash escape sequences in the corresponding argument.
Update as I didn't really get the question at first. It should simply be:
IFS=\" read __ KEY __ MESSAGE __ <<< "$DATA"
[[ $KEY == success ]] ## Gives $? = 0 if true or else 1 if false.
And you can examine it further:
case "$KEY" in
success)
echo "Success message: $MESSAGE"
exit 0
;;
error)
echo "Error message: $MESSAGE"
exit 1
;;
esac
Of course similar obvious tests can be done with it:
if [[ $KEY == success ]]; then
echo "It was successful."
else
echo "It wasn't."
fi
From your last comment it can be simply done as
IFS=\" read __ KEY __ MESSAGE __ <<< "$DATA"
echo "$DATA" ## Your really need to show $DATA and not $MESSAGE right?
[[ $KEY == success ]]
exit ## Exits with code based from current $?. Not necessary if you're on the last line of the script.
You probably already have python installed, which has json parsing in the standard library. Python is not a great language for one-liners in shell scripts, but here is one way to use it:
#!/bin/bash
DATA=$(wget -O - -q -t 1 http://localhost:8080/test_beat)
if python -c '
import json, sys
exit(1 if "error" in json.loads(sys.stdin.read()) else 0)' <<<"$DATA"
then
echo "SUCCESS: $DATA"
else
echo "ERROR: $DATA"
exit 1
fi
Given:
that you don't want to use JSON libraries.
and that the response you're parsing is simple and the only thing you care about is the presence of substring "success", I suggest the following simplification:
#!/bin/bash
wget -O - -q -t 1 http://localhost:8080/tester | grep -F -q '"success"'
exit $?
-F tells grep to search for a fixed (literal) string.
-q tells grep to produce no output and instead only reflect via its exit code whether a match was found or not.
exit $? simply exits with grep's exit code ($? is a special variable that reflects the most recently executed command's exit code).
Note that if you all you care about is whether wget's output contains "success", the above pipeline will do - no need to capture wget's output in an aux. variable.