Commands using cat (514)

  • install json-to-js as a npm global package


    0
    cat data.json | json-to-js | pbcopy
    minademian · 2018-12-14 15:55:41 42
  • Plain old `unzip` won't unzip output coming from STDOUT the ZIP file format includes a directory (index) at the end of the archive. This directory says where, within the archive each file is located and thus allows for quick, random access, without reading the entire archive. This would appear to pose a problem when attempting to read a ZIP archive through a pipe, in that the index is not accessed until the very end and so individual members cannot be correctly extracted until after the file has been entirely read and is no longer available. As such it appears unsurprising that most ZIP decompressors simply fail when the archive is supplied through a pipe. The directory at the end of the archive is not the only location where file meta information is stored in the archive. In addition, individual entries also include this information in a local file header, for redundancy purposes. From the `jar` manpage: > The jar command is a general-purpose archiving and compression tool, based on ZIP and the ZLIB compression format. JAR is smart enough to know how to handle these local file headers when the index is unavailable when reading through the pipe. (Most of the explanation in this description is taken from https://serverfault.com/a/589528/314226 , though they recommend using `bsdtar`, but that is not always available on systems) Show Sample Output


    0
    cat foo.zip | jar xv
    bbbco · 2019-01-14 22:08:19 33
  • Overwrites remote file without asking! Uses HTTPS proxy that supports CONNECT. Actually uses SSH and not SFTP to upload the file.


    0
    cat myFile.json | ssh root@remoteSftpServer -o "ProxyCommand=nc.openbsd -X connect -x proxyhost:proxyport %h %p" 'cat > myFile.json'
    casueps · 2020-01-22 11:00:20 107
  • Especially good for exported ipython files Show Sample Output


    0
    grep -v '^# In' viz.txt | cat -s > out.txt
    shantanuo · 2022-06-08 04:01:11 507
  • This command works only if the line "DROP TABLE IF EXISTS" exists for all tables in the mysqldump file. It acts like a state machine.


    0
    cat db_dump.sql | awk '/DROP TABLE IF EXISTS/ { skip = $5 ~ /table1|table2/ } !skip { print $0 }' > db_dump_filtered.sql
    stf42 · 2022-10-30 16:58:57 801
  • tells you the number of lines in said file, and then tail the last 100 lines ( or how many are messed up) then u take the total amount of lines and then subract the 100 or so lines u DONT WANT, then do a head -n $new_number and then redirect it to new file.db


    -1
    cat -n $file | tail -n 100 && head -n number-of-lines-you-want-to-keep > newfile
    bbelt16ag · 2009-02-15 01:02:10 9
  • In July 2008, there was an uproar over Foxconn motherboards feeding Linux installs incorrect ACPI information (http://ubuntu-virginia.ubuntuforums.org/showthread.php?t=869249). Foxconn has gladly corrected their mistake, but make sure it's not happening on your motherboard! After running the command, just view the 'dsdt.dsl' in any editor you like. Show Sample Output


    -1
    sudo aptitude -y install iasl && sudo cat /sys/firmware/acpi/tables/DSDT > dsdt.dat && iasl -d dsdt.dat
    brettalton · 2009-02-15 23:13:50 13
  • Be aware of using the --password argument as it will appear your password in plain text on the screen. You may use -p argument instead, it will prompt you to enter you password in hidden mode.


    -1
    cat schema.sql data.sql test_data.sql | mysql -u user --password=pass dbname
    tristan_ph · 2009-03-24 08:39:40 6
  • I'm sure almost everybody knows this by now. This command will pull the password for the admin login of any plesk machine. Show Sample Output


    -1
    cat /etc/psa/.psa.shadow
    jigglebilly · 2009-04-30 18:08:12 4
  • This is useful for displaying a portion of a FILE that contains an error at line NUMBER


    -1
    cat -n FILE | grep -C3 "^[[:blank:]]\{1,5\}NUMBER[[:blank:]]"
    lv4tech · 2009-05-17 18:19:55 8
  • VARNAMES='ID FORENAME LASTNAME ADDRESS CITY PHONE MOBILE MAIL ...' cat customer.csv | while read LINE ; do COUNT=1 for VAR in $VARNAMES ; do eval "${VAR}=`echo $LINE | /usr/bin/awk {'print $'$COUNT''}`" let COUNT=COUNT+1 done done Maybe you have a CSV-File with addresses, where you have to process each contact (one per line, write each value to own variable). Of course you can define every variable, but this way is more simple and faster (to write). VARNAMES includes the variable names. Pay attention: the number of names in VARNAMES have to be the same than in the CSV-file the fields. If the CSV is not seperated with ";", you can set the seperator after the awk-binary with -F"_" for example.


    -1
    VARNAMES='ID FORENAME LASTNAME ADDRESS CITY PHONE MOBILE MAIL' ; cat customer.csv | while read LINE ; do COUNT=1 ; for VAR in $VARNAMES ; do eval "${VAR}=`echo $LINE | /usr/bin/awk {'print $'$COUNT''}`" ; let COUNT=COUNT+1 ; done ; done
    GeckoDH · 2009-05-19 11:23:00 4
  • avoid mouse abuse and the constant struggle of balancing scroll velocity ... not to mention that burning sensation in your upper right shoulder ....


    -1
    cat large.xml | xclip
    copremesis · 2009-07-08 16:30:07 8
  • If you are downloading a big file (or even a small one) and the connection breaks or times out, use this command in order to RESUME the download where it failed, instead of having to start downloading from the beginning. This is a real win for downloading debian ISO images over a buggy DSL modem. Take the partially downloaded file and cat it into the STDIN of curl, as shown. Then use the "-C -" option followed by the URL of the file you were originally downloading. Show Sample Output


    -1
    cat file-that-failed-to-download.zip | curl -C - http://www.somewhere.com/file-I-want-to-download.zip >successfully-downloaded.zip
    linuxrawkstar · 2009-08-05 13:33:06 16

  • -1
    echo capitalize | { dd bs=1 count=1 conv=ucase 2> /dev/null; cat ;}
    twfcc · 2009-09-05 01:49:53 40
  • Some malicious program appends a iframe or script tag to you web pages on some server, use this command to clean them in batch.


    -1
    for f in *.html; do head -n -1 $f > temp; cat temp > $f; rm temp; done
    Sunng · 2009-10-12 12:49:18 5
  • Yep, is hard, but is a way more flexible using pipe.


    -1
    cat infile | while read str; do echo "$((++i)) - $str" ; done;
    glaudiston · 2009-12-09 14:05:09 3
  • Get Memeory Info


    -1
    cat /proc/meminfo
    svnlabs · 2010-01-22 16:48:03 3
  • You don't need to create an intermediate file, just pipe the output directly to tar command and use stin as file (put a dash after the f flag).


    -1
    cat 1.tar.gz 2.tar.gz | tar zxvif -
    psychopenguin · 2010-05-09 03:50:00 5
  • -r to use extended regex ^ begin line | alternative get 100 or 0-9 one or two times Show Sample Output


    -1
    cat file | sed -n -r '/^100$|^[0-9]{1,2}$/p'
    voyeg3r · 2010-05-15 19:15:56 5
  • thx Montecristo, thx hckhckhck


    -1
    cat > {filename} {your text} [^C | ^D]
    sphere64 · 2010-06-03 09:02:12 3
  • It works in every linux box Show Sample Output


    -1
    cat /proc/cpuinfo
    magicjohnson_ · 2010-09-24 09:27:58 3
  • Is a simple script for video streaming a movie


    -1
    cat video.ogg | nc -l -p 4232 & wget http://users.bshellz.net/~bazza/?nombre=name -O - & sleep 10; mplayer http://users.bshellz.net/~bazza/datos/name.ogg
    el_bazza · 2010-11-29 03:34:31 5
  • This command deletes the "newline" chars, so its output maybe unusable :)


    -1
    cat file | tr -d "\n"
    uzsolt · 2010-12-02 09:22:02 3
  • Change your drive letter as you wish. Using pv command for speed detect.First of all you must install pv command for usage. http://www.bayner.com/ kerim@bayner.com Show Sample Output


    -1
    cat /dev/sda | pv -r > /dev/null
    kerim · 2011-01-23 22:58:56 5

  • -1
    grabtweets() { curl -s -o $GT_TMP twitter.com/$1 | cat $GT_TMP | grep entry-content | sed -e :loop -e 's/<[^>]*>//g;/</N;//bloop' | sed 's/^[ \t]*//'; }
    gl101 · 2011-05-04 21:49:08 5
  • ‹ First  < 15 16 17 18 19 >  Last ›

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

Mount a partition from dd disk image
Assuming we have a disk image, ie. created by $dd if=/dev/sda of=image.dd we can check the image's partition layout with $fdisk -ul image.dd then, we substitute "x" with starting sector of the partition we want to mount. This example assumes that the disk uses 512 B sectors

Catch a proccess from a user and strace it.
It sits there in a loop waiting for a proccess from that user to spawn. When it does it will attach strace to it

rename all jpg files with a prefix and a counter

Plowshare, download files from cyberlocker like rapidshare megaupload ...etc
you need to have plowshare installed http://code.google.com/p/plowshare/ plowshare supports Megaupload, Rapidshare, 2Shared, 4Shared, ZShare, Badongo, Divshare.com, Depositfiles, Netload.in, Sendspace, Usershare, x7.to and some others file sharing services.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Display information sent by browser
Have netcat listen on port 8000, point browser to http://localhost:8000/ and you see the information sent. netcat terminates as soon as your browser disconnects. I tested this command on my Fedora box but linuxrawkstar pointed out that he needs to use $ nc -l -p 8000 instead. This depends on the netcat version you use. The additional '-p' is required by GNU netcat that for example is used by Debian but not by the OpenBSD netcat port used by my Fedora system.

Insert the last argument of the previous command
for example if you did a: $ ls -la /bin/ls then $ ls !$ is equivalent to doing a $ ls /bin/ls

Convert files from DOS line endings to UNIX line endings
Here "^M" is NOT "SHIFT+6" and "M". Type CTRL+V+M to get it instead. Its shortest and easy. And its sed!, which is available by default in all linux flavours.. no need to install extra tools like fromdos.

Losslessly rotate videos from your phone by 90 degrees.
Takes all the .3gp files in the directory, rotates them by 90 degrees, and saves them in the lossless ffv1 encoding. If this rotates in the wrong direction, you may want transponse=1 Re-encoding to ffv1 may result in a significant increase in file size, as it is a lossless format. Other applications may not recognize ffv1 if they don't use ffmpeg code. "huffyuv" might be another option for lossless saving of your transformations. The audio may be re-encoded as well, if the encoding used by your 3gp file doesn't work in a avi container.

Smart renaming
Use 'mmv' for mass renames. The globbing syntax is intuitive.


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: