EDIT 1
I'm having problems using the arguments given. Maybe it is the way I'm passing my arguments through NSTask? Any suggestions as to how I can do this?
NSTask *file_Task = [NSTask new];
[file_Task setLaunchPath:#"/usr/sbin/lsof"];
[file_Task setArguments:[NSArray arrayWithObjects:#"+p", the_Pid, nil]];
Good Afternoon Fellow Coders....
I'm using the following command:
lsof +p 13812
to get the list of a files accessed by a process. The thing is it is giving me a lot of additional information that I don't want such as TYPE, DEVICE, etc.
Is there an argument that I can add to the above command so that I get ONLY the NAME?
Thank you, thank you thank you! :)
Eric
You can use:
lsof -Fn +p 12345
This will output a list of lines, with the first being p followed by the process ID,
and all following lines consisting of n followed by the file name.
If you'd like to quickly preprocess this, you can do something similar to the following:
lsof -Fn +p 12345 | tail -n +2 | cut -c2-
See the lsof man page for more information, specifically under the OUTPUT FOR OTHER PROGRAMS heading.
try:
lsof | tr -s ' ' | cut -d' ' -f9
lsof +p 9174 | awk '{ print $9 }'
Listing the currently playing song (nfs file, accessed by user mpd):
$ sudo lsof -N -a -u mpd -Fn |
sed '/n/!d; s/^n//'
/R/audio/[...] Jay-Jay Johanson , So Tell The Girls That I Am Back.mp3
The sed part deletes any lines not starting with n and removes n in the final output.
Related
I'm trying to figure out a command to parse the following file content:
Operation=GET
Type=HOME
Counters=CacheHit=0,Exception=1,Validated=0
I need to extract Exception=1 into its own line. I'm fiddling with awk, sed and grep but not making much progress. Does anyone have any tips on using any unix command to perform this?
Thanks
Since your file is close to bash syntax, there is a fun little trick you can do to make bash itself parse the file. First, use some program like tr to transform the input into a something bash can parse, and then "source" that, which will create shell variables you can expand later to get the values.
source <(tr , $'\n' < file_name_goes_here)
echo $Exception
Many ways to do this. Here is one assuming the file is called "file.txt". Grab the line you want, replace everything from the start of the line up to Except with just Except, then pull out the first field using comma as the delimiter.
$ grep Exception file.txt | sed 's/.*Except/Except/g' | cut -d, -f 1
Exception=1
If you wanted to use gawk:
$ grep Exception file.txt | sed 's/.*Except/Except/g' | gawk -F, '{print $1}'
Exception=1
or just using grep and sed:
$ grep Exception file.txt | sed 's/.*\(Exception=[0-9]*\).*/\1/g'
Exception=1
or as #sheltter reminded me:
$ egrep -o "Exception=[0-9]+" file.txt
Exception=1
No need to use a mix of commands.
awk -F, 'NR==2 {print RS$1}' RS="Exception" file
Exception=1
Here we split the line by the keyword we look for RS="Exception"
If the line has two record (only when keyword is found), then
print first field, separated using command, with Record selector.
PS This only works if you have one Exception field
I do use grep a lot, but I would love to improve a bit.
Regarding the question. I wanted to narrow the man entry to find the explanation of what the -v in grep -v 'pattern' filename stood for, mainly this:
-v, --invert-match
Selected lines are those not matching any of the specified patterns.
Thus, to find the next five lines after the line which contains -v I tried:
man grep | grep -A 5 -v
and
man grep | grep -A 5 '-v'
but they return:
usage: grep [-abcDEFGHhIiJLlmnOoqRSsUVvwxZ] [-A num] [-B num] [-C[num]]
[-e pattern] [-f file] [--binary-files=value] [--color=when]
[--context[=num]] [--directories=action] [--label] [--line-buffered]
[--null] [pattern] [file ...]
This confuses me since:
man grep | grep -A 5 'Selected'
and
man grep | grep -A 5 Selected
do work.
What is wrong in my approach? Is there any easier way to achieve what I need?
One approach is to parse the Info documents for the command directly. If you run info grep (or other command) you will often find much more detailed and better-structured documentation, which will let you pin-point just the section you need.
Here's a function that will print out the relevant Info section for an option/variable/etc:
info_search() {
info --subnodes "$1" -o - 2>&- \
| awk -v RS='' "/(^|\n)(‘|'|\`)$2((,|\[| ).*)?(’|')\n/"
}
This should work on Linux/macOS/BSD. Output is like:
$ info_search grep -v
‘-v’
‘--invert-match’
Invert the sense of matching, to select non-matching lines. (‘-v’
is specified by POSIX.)
$ info_search gawk RS
'RS == "\n"'
Records are separated by the newline character ('\n'). In effect,
every line in the data file is a separate record, including blank
...
$ info_search bash -i
`-i'
Force the shell to run interactively. Interactive shells are
...
I would like a dead-simple way to query my gps location from a usb dongle from the unix command line.
Right now, I know I've got a functioning software and hardware system, as evidenced by the success of the cgps command in showing me my position. I'd now like to be able to make short requests for my gps location (lat,long in decimals) from the command line. my usb serial's path is /dev/ttyUSB0 and I'm using a Global Sat dongle that outputs generic NMEA sentences
How might I accomplish this?
Thanks
telnet 127.0.0.1 2947
?WATCH={"enable":true}
?POLL;
gives you your answer, but you still need to separate the wheat from the chaff. It also assumes the gps is not coming in from a cold start.
A short script could be called, e.g.;
#!/bin/bash
exec 2>/dev/null
# get positions
gpstmp=/tmp/gps.data
gpspipe -w -n 40 >$gpstmp"1"&
ppid=$!
sleep 10
kill -9 $ppid
cat $gpstmp"1"|grep -om1 "[-]\?[[:digit:]]\{1,3\}\.[[:digit:]]\{9\}" >$gpstmp
size=$(stat -c%s $gpstmp)
if [ $size -gt 10 ]; then
cat $gpstmp|sed -n -e 1p >/tmp/gps.lat
cat $gpstmp|sed -n -e 2p >/tmp/gps.lon
fi
rm $gpstmp $gpstmp"1"
This will cause 40 sentences to be output and then grep lat/lon to temporary files and then clean up.
Or, from GPS3 github repository place the alpha gps3.py in the same directory as, and execute, the following Python2.7-3.4 script.
from time import sleep
import gps3
the_connection = gps3.GPSDSocket()
the_fix = gps3.DataStream()
try:
for new_data in the_connection:
if new_data:
the_fix.refresh(new_data)
if not isinstance(the_fix.TPV['lat'], str): # check for valid data
speed = the_fix.TPV['speed']
latitude = the_fix.TPV['lat']
longitude = the_fix.TPV['lon']
altitude = the_fix.TPV['alt']
print('Latitude:', latitude, 'Longitude:', longitude)
sleep(1)
except KeyboardInterrupt:
the_connection.close()
print("\nTerminated by user\nGood Bye.\n")
If you want it to close after one iteration also import sys and then replace sleep(1) with sys.exit()
much easier solution:
$ gpspipe -w -n 10 | grep -m 1 lon
{"class":"TPV","device":"tcp://localhost:4352","mode":2,"lat":11.1111110000,"lon":22.222222222}
source
You can use my script : gps.sh return "x,y"
#!/bin/bash
x=$(gpspipe -w -n 10 |grep lon|tail -n1|cut -d":" -f9|cut -d"," -f1)
y=$(gpspipe -w -n 10 |grep lon|tail -n1|cut -d":" -f10|cut -d"," -f1)
echo "$x,$y"
sh gps.sh
43.xx4092000,6.xx1269167
Putting a few of the bits of different answers together with a bit more jq work, I like this version:
$ gpspipe -w -n 10 | grep -m 1 TPV | jq -r '[.lat, .lon] | #csv'
40.xxxxxx054,-79.yyyyyy367
Explanation:
(1) use grep -m 1 after invoking gpspipe, as used by #eadmaster's answer, because the grep will exit as soon as the first match is found. This gets you results faster instead of having to wait for 10 lines (or using two invocations of gpspipe).
(2) use jq to extract both fields simultaneously; the #csv formatter is more readable. Note the use of jq -r (raw output), so that the output is not put in quotes. Otherwise the output would be "40.xxxx,-79.xxxx" - which might be fine or better for some applications.
(3) Search for the TPV field by name for clarity. This is the "time, position, velocity" record, which is the one we want for extracting the current lat & lon. Just searching for "lat" or "lon" risks getting confused by the GST object that some GPSes may supply, and in that object, 'lat' and 'lon' are the standard deviation of the position error, not the position itself.
Improving on eadmaster's answer here is a more elegant solution:
gpspipe -w -n 10 | jq -r '.lon' | grep "[[:digit:]]" | tail -1
Explanation:
Ask from gpsd 10 times the data
Parse the received JSONs using jq
We want only numeric values, so filter using grep
We want the last received value, so use tail for that
Example:
$ gpspipe -w -n 10 | jq -r '.lon' | grep "[[:digit:]]" | tail -1
28.853181286
I am doing a describe on a file:
ct desc -ahlink -all 5.txt
5.txt##/main/52
Hyperlinks:
Merge <- /vobs/TESTVOB/5.txt##/main/test_branch/1
Merge <- /vobs/TESTVOB/5.txt##/main/test_branch/2
Is there a way in clearcase using -fmt something to get the last hyperlink from the describe command without using unix commands to achieve it?
If not can someone suggest me the appropriate unix command to get the desired output?
I tried this command:
ct desc -ahlink -all 5.txt | grep Merge | cut -d "-" -f2
and this gives me:
/vobs/TESTVOB/5.txt##/main/test_branch/1
/vobs/TESTVOB/5.txt##/main/test_branch/2
I only want:
/vobs/TESTVOB/5.txt##/main/test_branch/2
Thanks in advance for your help
I don't know of a native way to get that last hyperlink.
So using a unix command like tail should be enough:
ct desc -ahlink -all 5.txt | grep Merge | tail -1 | cut -d "-" -f2
I want to get a list of all the files in a directory, like with ls, so that each filename will be on a seperate line, without the extra details supplied by ls -l. I looked at ls --help and didn't find a solution. I tried doing
ls -l | cut --fields=9 -d" "
but ls doesn't use a fixed number of spaces between columns. Any idea on how to do this, preferably in one line?
ls -1
That is a number, not small L.
ls -1. From the help:
-1 list one file per line
Works on cygwin and FreeBSD, so it's probably not too GNU-specific.
solution without pipe-ing :-)
ls --format single-column
Note that the long options are only supported on the GNU coreutils where BSD ls only supports the short arguments -1
Perhaps:
ls | awk '{print $NF}'
ls | cat
...
or possibly, ls -1
Use sed command to list single columns
ls -l | sed 's/\(^[^0-9].\*[0-9]\*:[0-9]\*\) \(.*\)/\2/'
Try this:
$ ls | xargs -n num
Here num is number of columns you want to list in.
first you can use this. it will display the one file per line.
ls -l | sed 's/(.* )(.*)$/\2/'
or else you can use thus
find . -maxdepth 1 | sed 's/.///'
both the things are the same.
This is also working: echo -e "\n$(ls)"
This will also do
ls -l | awk '{print $NF}'