Commands using gcc (17)

  • Try modifying the numbers in the "(i*(i>>8|i>>9)&46&i>>8))^(i&i>>13|i>>6)" part. Crudely stolen from http://www.xkcdb.com/9067


    10
    echo "main(i){for(i=0;;i++)putchar(((i*(i>>8|i>>9)&46&i>>8))^(i&i>>13|i>>6));}" | gcc -x c - && ./a.out | aplay
    SNDR · 2013-02-17 21:31:04 2

  • 8
    gcc -dM -E - < /dev/null
    ohe · 2009-10-28 14:13:19 1
  • outputs a f=220Hz guitar string sound (fifth string A) needs ALSA


    7
    f=220;echo "int s=16e3/$f;main(i){unsigned char v[s];read(0,v,s);for(;;)putchar(v[i%s]=(v[i%s]+v[++i%s])/2);}"|gcc -x c -&&./a.out</dev/urandom|aplay -d 2
    tehdog · 2013-06-28 14:52:53 3
  • /lib/ld-linux.so.2 is the runtime linker/loader for ELF binaries on Linux. =(cmd) is a zsh trick to take the output for the command "inside" it and save it to a temporary file. echo -e 'blah' | gcc -x c -o /dev/stdout - pipes the C source to gcc. -x c tells gcc that it's compiling C (which is required if it's reading from a pipe). -o /dev/stdout - tells it to write the binary to standard output and read the source from standard input. because of the the =() thing, the compiled output is stashed in a tempfile, which the loader then runs and executes, and the shell tosses the tempfile away immediately after running it. Show Sample Output


    6
    /lib/ld-linux.so.2 =(echo -e '#include <stdio.h>\nint main(){printf("c one liners\\n");}' | gcc -x c -o /dev/stdout -)
    mrtheplague · 2009-02-20 06:06:29 4
  • doesn't need /dev/null Show Sample Output


    4
    gcc -dM -E - <<<''
    bucciarati · 2009-10-28 14:26:56 0
  • Lists all macros and their values defined by gcc. Show Sample Output


    3
    gcc -dM -E - </dev/null
    slower · 2013-09-30 15:08:34 0

  • 2
    gcc -dM -E - < /dev/null
    lucasrangit · 2012-04-27 17:37:50 0
  • another one


    0
    echo | gcc -dM -E -
    Byung · 2011-05-09 09:59:24 0

  • 0
    for c in gcc bison dialog bc asdf; do if ! which $c >/dev/null; then echo Required program $c is missing ; exit 1; fi; done
    Mozai · 2011-06-27 12:54:02 0

  • 0
    gcc -E code.c | sed '/^\#/d' | indent -st -i2 > code-x.c
    enikulenkov · 2012-06-18 22:20:33 0
  • Something I pulled off 4chan, it plays a tune.


    0
    echo "main(i){for(i=0;;i++)putchar(((i*(i>>8|i>>9)&46&i >>8))^(i&i>>13|i>>6));}" | gcc -x c - && ./a.out | aplay
    r0nd0n · 2013-01-09 21:48:23 0
  • Install Ksuperkey one command in Kubuntu. You must manually add ksuperkey to autostart in System Settings KDE.


    0
    sudo apt-get install git gcc make libx11-dev libxtst-dev pkg-config -y && git clone https://github.com/hanschen/ksuperkey.git && cd ksuperkey && make && sudo mv ksuperkey /usr/bin/ksuperkey && cd ~ && rm -rf ksuperkey
    FadeMind · 2013-04-17 07:12:46 0

  • 0
    vim test.c && gcc -x c -o a.out test.c && ./a.out && rm a.out test.c
    ari2015 · 2013-09-08 15:09:09 0
  • This is a quick hack to make a gcc caller. Since it runs with gcc instead of tcc, it's a bit more trustworthy as far as the final answers of things go. Show Sample Output


    -3
    alias cstdin='echo "Ctrl-D when done." && gcc -Wall -o ~/.stdin.exe ~/.stdin.c && ~/.stdin.exe'
    taliver · 2009-11-19 16:38:51 1
  • It's hard to beat C. This is just slightly faster than the bc version on my machine. real 0m26.856s user 0m25.030s sys 0m0.024s Requirements: libgmp headers, gcc. Show Sample Output


    -5
    gcc -x c -o /tmp/out - -lgmp <<< '#include <stdlib.h> ... SEE SAMPLE OUTPUT FOR FULL COMMAND
    hank · 2009-09-10 02:10:46 3

  • -6
    gcc -Wall -Werror -o prog prog.c || rm -f prog.c
    devoid · 2009-02-05 17:26:51 1
  • Compile *.c files with "gcc -Wall" in actual directory, using as output file the file name without extension.


    -7
    ls *.c | while read F; do gcc -Wall -o `echo $F | cut -d . -f 1 - ` $F; done
    pichinep · 2009-08-28 13:01:56 1

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

Define a quick calculator function
POSIX compliant arithmetic evaluation. = 10*2+3

check the fucking weather
grab the weather, with a little expletive fun. replace the 48104 with a US zipcode, or the name of your city (such as ZIP="oslo"), unless you want to know what the weather is like for me (and that's fine too)

bash script to zip a folder while ignoring git files and copying it to dropbox
Better tool for exporting git's repository is Git itself!

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"

A DESTRUCTIVE command to render a drive unbootable
Overwrites the boot sector. Since this doesn't overwrite any data, you can usually recover by re-creating the partition table exactly the same as before you zeroed it. This can also help sometimes if you install a new drive in a Windows machine which can't read it.

mirrors directory to a ftp server
http://lftp.yar.ru/

Auto-log commands
A quick alias I use right before logging into a server so that I have a log of the transactions as well as the ability to re-connect from another computer. Useful for when your boss says "what commands did you run again on that server?" and you had already closed the terminal ;) I wrapped it in a script now, with more features, but this is the heart of it. Never leave home without it.

Update a tarball
This will update the tarball, adding files that have changed since the last update. This assumes that the tarball is in the same directory as the files being archived. N.B. This command can't be used on compressed tarballs. N.B. This will add the updated files to the tarball, so that the tarball will have two versions of each file. This will make the tarball larger, but doesn't have any other significant effect.

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 multiple flac files to mp3
make sure that flac and lame are installed sudo apt-get install lame flac


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: