JQ adds single quotes while saving in environment variables - environment-variables

OK, this might be a silly question. I've got the test.json file:
{
"timestamp": 1234567890,
"report": "AgeReport"
}
What I want to do is to extract timestamp and report values and store them in some env variables:
export $(cat test.json | jq -r '#sh "TIMESTAMP=\(.timestamp) REPORT=\(.report)"')
and the result is:
echo $TIMESTAMP $REPORT
1234567890 'AgeReport'
The problem is that those single quotes break other commands.
How can I get rid of those single quotes?
NOTE: I'm gonna leave the accepted answer as is, but see #Inian's answer for a better solution.

Why make it convoluted with using eval and have a quoting mess? Rather simply emit the variables by joining them with NULL (\u0000) and read it back in the shell environment
{
IFS= read -r -d '' TIMESTAMP
IFS= read -r -d '' REPORT
} < <(jq -r '(.timestamp|tostring) + "\u0000" + .report + "\u0000"' test.json)
This makes your parsing more robust by making the fields joined by NULL delimiter, which can't be part of your string sequence.

From the jq man-page, the #sh command converts its input to be
escaped suitable for use in a command-line for a POSIX shell.
So, rather than attempting to splice the output of jq into the shell's export command which would require carefully removing some quoting, you can generate the entire commandline inside jq, and then execute it with eval:
eval "$(
cat test.json |\
jq -r '#sh "export TIMESTAMP=\(.timestamp) REPORT=\(.report)"'
)"

Related

using grep command to get spectfic word [LINUX]

I have a test.txt file with links for example:
google.com?test=
google.com?hello=
and this code
xargs -0 -n1 -a FUZZvul.txt -d '\n' -P 20 -I % curl -ks1L '%/?=DarkLotus' | grep -a 'DarkLotus'
When I type a specific word, such as DarkLotus, in the terminal, it checks the links in the file and it brings me the word which is reflected in the links i provided in the test file
There is no problem here, the problem is that I have many links, and when the result appears in the terminal, I do not know which site reflected the DarkLotus word.
How can i do it?
Try -n option. It shows the line number of file with the matched line.
Best Regards,
Haridas.
I'm not sure what you are up to there, but can you invert it? grep by default prints matching lines. The problem here is you are piping the input from the stdout of the previous commands into grep, and that can lack context at grep. Since you have a file to work with:
$ grep 'DarkLotus' FUZZvul.txt
If your intention is to also follow the link then it might be easier to write a bash script:
#!/bin/bash
for line in `grep 'DarkLotus FUZZvul.txt`
do
link=# extract link from line
echo ${link}
curl -ks1L ${link}
done
Then you could make your script accept user input:
#/bin/bash
word="${0}"
for line in `grep ${word} FUZZvul.txt`
...
and then
$ my_link_getter "DarkLotus"
https://google?somearg=DarkLotus
...
And then you could make the txt file a parameter.
etc.

Tool for edit lvm.conf file

is there any lvm.conf editor?
I'm trying to set global_filter, use_lvmtad and some other options, currently using sed:
sed -i /etc/lvm/lvm.conf \
-e "s/use_lvmetad = 1/use_lvmetad = 0/" \
-e "/^ *[^#] *global_filter/d" \
-e "/^devices {/a\ global_filter = [ \"r|/dev/drbd.*|\", \"r|/dev/dm-.*|\", \"r|/dev/zd.*|\" ]"
but I don't like this too much, is there any better way?
I found only lvmconfig tool, but it can only display certain configuration sections, and can't edit them.
If you using Ubuntu variant then you can use the LVM GUI to configure and manage the LVM. Refer this link
It seems that augtool is exactly what I was looking for.
These two packages should be enough to proper processing lvm.conf file:
apt install augeas-tools augeas-lenses
Example usage:
augtool print /files/etc/lvm/lvm.conf
And you should get the whole parse tree on stdout.
If the parser fails you won’t get any output, print the error message using:
augtool print /files/etc/lvm/lvm.conf/error
The augtool equivalent for the sed command from the original question:
augtool -s <<EOT
set /files/etc/lvm/lvm.conf/global/dict/use_lvmetad/int "0"
rm /files/etc/lvm/lvm.conf/devices/dict/global_filter
set /files/etc/lvm/lvm.conf/devices/dict/global_filter/list/0/str "r|^/dev/drbd.*|"
set /files/etc/lvm/lvm.conf/devices/dict/global_filter/list/1/str "r|/dev/dm-.*|"
set /files/etc/lvm/lvm.conf/devices/dict/global_filter/list/2/str "r|/dev/zd.*|"
EOT

TAR with --to-command

I'd like to calculate MD5 for all files in a tar archive. I tried tar with --to-command.
tar -xf abc.tar --to-command='md5sum'
it outputs like below.
cb6bf052c851c1c30801ef27c9af1968 -
f509549ab4eeaa84774a4af0231cccae -
Then I want to replace '-' with file name.
tar -xf abc.tar --to-command='md5sum | sed "s#-#$TAR_FILENAME#"' it reports error.
md5sum: |: No such file or directory
md5sum: sed: No such file or directory
md5sum: s#-#./bin/busybox#: No such file or directory
tar: 23255: Child returned status 1
You don't have a shell so this won't work (you also might see that the | gets to md5sum as an argument). one way could be to invoke the shell yourself, but there is some hassle with nested quotes:
tar xf some.tar --to-command 'sh -c "md5sum | sed \"s|-|\$TAR_FILENAME|\""'
At first, it's better to avoid using sed, not only because it's slow, but because $TAR_FILENAME can contain magic chars to be interpreted by sed (you already noticed that, having to use # instead of / for substitution command, didnt you?). Use deadproof solution, like head, followed by echoing actual filename.
Then, as Patrick mentions in his answer, you can't use complex commands without having them wrapped with shell, but for convenience I suggest to use built-it shell escapement ability, for bash it's printf '%q' "something", so the final command be like:
tar xf some.tar \
--to-command="sh -c $(printf '%q' 'md5sum | head -c 34 && printf "%s\n" "$TAR_FILENAME"')"
"34" is number of bytes before file name in md5sum output format; && instead of ; to allow md5sum's error code (if any) reach tar; printf instead of echo used because filenames with leading "-" may be interpreted by echo as options.

Shell: Find Matching Lines Across Many Files

I am trying to use a shell script (well a "one liner") to find any common lines between around 50 files.
Edit: Note I am looking for a line (lines) that appears in all the files
So far i've tried grep grep -v -x -f file1.sp * which just matches that files contents across ALL the other files.
I've also tried grep -v -x -f file1.sp file2.sp | grep -v -x -f - file3.sp | grep -v -x -f - file4.sp | grep -v -x -f - file5.sp etc... but I believe that searches using the files to be searched as STD in not the pattern to match on.
Does anyone know how to do this with grep or another tool?
I don't mind if it takes a while to run, I've got to add a few lines of code to around 500 files and wanted to find a common line in each of them for it to insert 'after' (they were originally just c&p from one file so hopefully there are some common lines!)
Thanks for your time,
When I first read this I thought you were trying to find 'any common lines'. I took this as meaning "find duplicate lines". If this is the case, the following should suffice:
sort *.sp | uniq -d
Upon re-reading your question, it seems that you are actually trying to find lines that 'appear in all the files'. If this is the case, you will need to know the number of files in your directory:
find . -type f -name "*.sp" | wc -l
If this returns the number 50, you can then use awk like this:
WHINY_USERS=1 awk '{ array[$0]++ } END { for (i in array) if (array[i] == 50) print i }' *.sp
You can consolidate this process and write a one-liner like this:
WHINY_USERS=1 awk -v find=$(find . -type f -name "*.sp" | wc -l) '{ array[$0]++ } END { for (i in array) if (array[i] == find) print i }' *.sp
old, bash answer (O(n); opens 2 * n files)
From #mjgpy3 answer, you just have to make a for loop and use comm, like this:
#!/bin/bash
tmp1="/tmp/tmp1$RANDOM"
tmp2="/tmp/tmp2$RANDOM"
cp "$1" "$tmp1"
shift
for file in "$#"
do
comm -1 -2 "$tmp1" "$file" > "$tmp2"
mv "$tmp2" "$tmp1"
done
cat "$tmp1"
rm "$tmp1"
Save in a comm.sh, make it executable, and call
./comm.sh *.sp
assuming all your filenames end with .sp.
Updated answer, python, opens only each file once
Looking at the other answers, I wanted to give one that opens once each file without using any temporary file, and supports duplicated lines. Additionally, let's process the files in parallel.
Here you go (in python3):
#!/bin/env python
import argparse
import sys
import multiprocessing
import os
EOLS = {'native': os.linesep.encode('ascii'), 'unix': b'\n', 'windows': b'\r\n'}
def extract_set(filename):
with open(filename, 'rb') as f:
return set(line.rstrip(b'\r\n') for line in f)
def find_common_lines(filenames):
pool = multiprocessing.Pool()
line_sets = pool.map(extract_set, filenames)
return set.intersection(*line_sets)
if __name__ == '__main__':
# usage info and argument parsing
parser = argparse.ArgumentParser()
parser.add_argument("in_files", nargs='+',
help="find common lines in these files")
parser.add_argument('--out', type=argparse.FileType('wb'),
help="the output file (default stdout)")
parser.add_argument('--eol-style', choices=EOLS.keys(), default='native',
help="(default: native)")
args = parser.parse_args()
# actual stuff
common_lines = find_common_lines(args.in_files)
# write results to output
to_print = EOLS[args.eol_style].join(common_lines)
if args.out is None:
# find out stdout's encoding, utf-8 if absent
encoding = sys.stdout.encoding or 'utf-8'
sys.stdout.write(to_print.decode(encoding))
else:
args.out.write(to_print)
Save it into a find_common_lines.py, and call
python ./find_common_lines.py *.sp
More usage info with the --help option.
Combining this two answers (ans1 and ans2) I think you can get the result you are needing without sorting the files:
#!/bin/bash
ans="matching_lines"
for file1 in *
do
for file2 in *
do
if [ "$file1" != "$ans" ] && [ "$file2" != "$ans" ] && [ "$file1" != "$file2" ] ; then
echo "Comparing: $file1 $file2 ..." >> $ans
perl -ne 'print if ($seen{$_} .= #ARGV) =~ /10$/' $file1 $file2 >> $ans
fi
done
done
Simply save it, give it execution rights (chmod +x compareFiles.sh) and run it. It will take all the files present in the current working directory and will make an all-vs-all comparison leaving in the "matching_lines" file the result.
Things to be improved:
Skip directories
Avoid comparing all the files two times (file1 vs file2 and file2 vs file1).
Maybe add the line number next to the matching string
Hope this helps.
Best,
Alan Karpovsky
See this answer. I originally though a diff sounded like what you were asking for, but this answer seems much more appropriate.

How can I tell from a within a shell script if the shell that invoked it is an interactive shell?

I'm trying to set up a shell script that will start a screen session (or rejoin an existing one) only if it is invoked from an interactive shell. The solution I have seen is to check if $- contains the letter "i":
#!/bin/sh -e
echo "Testing interactivity..."
echo 'Current value of $- = '"$-"
if [ `echo \$- | grep -qs i` ]; then
echo interactive;
else
echo noninteractive;
fi
However, this fails, because the script is run by a new noninteractive shell, invoked as a result of the #!/bin/sh at the top. If I source the script instead of running it, it works as desired, but that's an ugly hack. I'd rather have it work when I run it.
So how can I test for interactivity within a script?
Give this a try and see if it does what you're looking for:
#!/bin/sh
if [ $_ != $0 ]
then
echo interactive;
else
echo noninteractive;
fi
The underscore ($_) expands to the absolute pathname used to invoke the script. The zero ($0) expands to the name of the script. If they're different then the script was invoked from an interactive shell. In Bash, subsequent expansion of $_ gives the expanded argument to the previous command (it might be a good idea to save the value of $_ in another variable in order to preserve it).
From man bash:
0 Expands to the name of the shell or shell script. This is set
at shell initialization. If bash is invoked with a file of com‐
mands, $0 is set to the name of that file. If bash is started
with the -c option, then $0 is set to the first argument after
the string to be executed, if one is present. Otherwise, it is
set to the file name used to invoke bash, as given by argument
zero.
_ At shell startup, set to the absolute pathname used to invoke
the shell or shell script being executed as passed in the envi‐
ronment or argument list. Subsequently, expands to the last
argument to the previous command, after expansion. Also set to
the full pathname used to invoke each command executed and
placed in the environment exported to that command. When check‐
ing mail, this parameter holds the name of the mail file cur‐
rently being checked.
$_ may not work in every POSIX compatible sh, although it probably works in must.
$PS1 will only be set if the shell is interactive. So this should work:
if [ -z "$PS1" ]; then
echo noninteractive
else
echo interactive
fi
try tty
if tty 2>&1 |grep not ; then echo "Not a tty"; else echo "a tty"; fi
man tty :
The tty utility writes the name of the terminal attached to standard
input to standard output. The name that is written is the string
returned by ttyname(3). If the standard input is not a terminal, the
message ``not a tty'' is written.
You could try using something like...
if [[ -t 0 ]]
then
echo "Interactive...say something!"
read line
echo $line
else
echo "Not Interactive"
fi
The "-t" switch in the test field checks if the file descriptor given matches a terminal (you could also do this to stop the program if the output was going to be printed to a terminal, for example). Here it checks if the standard in of the program matches a terminal.
Simple answer: don't run those commands inside ` ` or [ ].
There is no need for either of those constructs here.
Obviously I can't be sure what you expected
[ `echo \$- | grep -qs i` ]
to be testing, but I don't think it's testing what you think it's testing.
That code will do the following:
Run echo \$- | grep -qs i inside a subshell (due to the ` `).
Capture the subshell's standard output.
Replace the original ` ` expression with a string containing that output.
Pass that string as an argument to the [ command or built-in (depending on your shell).
Produce a successful return code from [ only if that string was nonempty (assuming the string didn't look like an option to [).
Some possible problems:
The -qs options to grep should cause it to produce no output, so I'd expect [ to be testing an empty string regardless of what $- looks like.
It's also possible that the backslash is escaping the dollar sign and causing a literal 'dollar minus' (rather than the contents of a variable) to be sent to grep.
On the other hand, if you removed the [ and backticks and instead said
if echo "$-" | grep -qs i ; then
then:
your current shell would expand "$-" with the value you want to test,
echo ... | would send that to grep on its standard input,
grep would return a successful return code when that input contained the letter i,
grep would print no output, due to the -qs flags, and
the if statement would use grep's return code to decide which branch to take.
Also:
no backticks would replace any commands with the output produced when they were run, and
no [ command would try to replace the return code of grep with some return code that it had tried to reconstruct by itself from the output produced by grep.
For more on how to use the if command, see this section of the excellent BashGuide.
If you want to test the value of $- without forking an external process (e.g. grep) then you can use the following technique:
if [ "${-%i*}" != "$-" ]
then
echo Interactive shell
else
echo Not an interactive shell
fi
This deletes any match for i* from the value of $- then checks to see if this made any difference.
(The ${parameter/from/to} construct (e.g. [ "${-//[!i]/}" = "i" ] is true iff interactive) can be used in Bash scripts but is not present in Dash, which is /bin/sh on Debian and Ubuntu systems.)

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