Commands using cat (514)

  • convert JSON object to JavaScript object literal

    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
  • Extract a Zip File from STDOUT with the Jar Command

    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
  • SFTP upload through HTTPS proxy

    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
  • remove junk

    Especially good for exported ipython files Show Sample Output


    0
    grep -v '^# In' viz.txt | cat -s > out.txt
    shantanuo · 2022-06-08 04:01:11 508
  • MySQL: Filter out specific tables from an existing mysqldump file with awk

    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
  • removing those pesky malformed lines at the end of a text file..

    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
  • View your motherboard's ACPI tables (in Debian & Ubuntu)

    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
  • Load multiple sql script in mysql

    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
  • Retrieve Plesk Admin Password

    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
  • display portion of a file

    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
  • Create variables from a list of names

    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
  • cat large file to clipboard

    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
  • use curl to resume a failed download

    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
  • Capitalize the word with dd


    -1
    echo capitalize | { dd bs=1 count=1 conv=ucase 2> /dev/null; cat ;}
    twfcc · 2009-09-05 01:49:53 40
  • remove the last line of all html files in a directory

    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
  • prints line numbers

    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

    Get Memeory Info


    -1
    cat /proc/meminfo
    svnlabs · 2010-01-22 16:48:03 3
  • Merge tarballs

    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
  • sed - match numbers between 1-100

    -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
  • Quickly create simple text file from command line w/o using vi/emacs

    thx Montecristo, thx hckhckhck


    -1
    cat > {filename} {your text} [^C | ^D]
    sphere64 · 2010-06-03 09:02:12 3
  • CPU architecture details

    It works in every linux box Show Sample Output


    -1
    cat /proc/cpuinfo
    magicjohnson_ · 2010-09-24 09:27:58 3
  • Send and streamming video to web

    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
  • Join lines

    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
  • Detect your computer's harddisk read speed without disk cache speed

    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
  • view someone's twitter stream from terminal


    -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
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Stoppable sleep
A nice way to interrupt a sleep with a signal.

Copy an element from the previous command
'n' is a non-negative integer. Using 0 will expand to the name of the previous command.

Annoying PROMPT_COMMAND animation
unset PROMPT_COMMAND to disable.

Use /dev/full to test language I/O-failsafety
The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation. In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.

Remove color codes (special characters) with sed
Removes ANSI color and end of line codes to the [{attr1};...;{attrn}m format.

Terminal Escape Code Zen - Strace and Tput
Depending on the TERM, the terminfo version, ncurses version, etc.. you may be using a varied assortment of terminal escape codes. With this command you can easily find out exactly what is going on.. This is terminal escape zen! $ ( 2>&2 strace -f -F -e write -s 1000 sh -c 'echo -e "initc\nis2\ncnorm\nrmso\nsgr0" | tput -S' 2>&1 ) | grep -o '"\\[^"]*"' --color=always "\33]4;%p1%d;rgb:%p2%{255}%*%{1000}%/%2.2X/%p3%{255}%*%{1000}%/%2.2X/%p4%{255}%*%{1000}%/%2.2X\33\\\33[!p\33[?3;4l\33[4l\33>\33[?12l\33[?25h\33[27m\33(B\33[m" Lets say you want to find out what you need to echo in order to get the text to blink.. $ echo -e "`tput blink`This will blink`tput sgr0` This wont" Now you can use this function instead of calling tput (tput is much smarter for portable code because it works differently depending on the current TERM, and tput -T anyterm works too.) to turn that echo into a much faster executing code. tput queries files, opens files, etc.. but echo is very strait and narrow. So now you can do this: $ echo -e "\33[5mThis will blink\33(B\33[m This wont" More at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Show a curses based menu selector
Not so much handy by itself, but very nice in shell scripts. This makes you a handy ncurses based checklist. Much like terminal installers, just use the arrow keys and hit 'Space' to adjust the selections. Returns all selected tags as strings, with no newline at the end. So, your output will be something like: "one" "two" "three" "four" "etc" For those who prefer bash expansion over gratuitious typing: $ whiptail --checklist "Simple checkbox menu" 12 35 3 $(echo {one,two,three,four}" '' 0"} ) Things to note: The height must includes the outer border and padding: add 7 to however many items you want to show up at the same time. If the status is 1, it will be selected by default. anything else, will be deselected.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

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