In `rm`, 

 - `-r` stands for _recursive_
 - `-f` stands for _force_


Doc :

    man rm

said :

&gt;         -f, --force
&gt;                ignore nonexistent files and arguments, never prompt
&gt;  
&gt;  
&gt;         -r, -R, --recursive
&gt;                remove directories and their contents recursively

`rm` means remove

`r` means recursive, which you have to use when removing an entire folder
`f` means force removal

combined, `rm -rf someDirectory` means **force the recursive removal of someDirectory**

  -r       
&gt; Recursively removes directories and  subdirectories
              in the argument list. The directory will be emptied
              of files and removed. The user is normally prompted
              for  removal of any write-protected files which the
              directory contains. The write-protected  files  are
              removed  without  prompting,  however,  if  the  -f
              option is used, or if the standard input is  not  a
              terminal and the -i option is not used.


I configured a custom analyzer and put some documents into the index. Now I want to debug my settings so I can see which n-grams actually made it into the index.

When I used Solr before, there was a possibility to see which strings were saved in the index as keys and also their frequency.

How can I view the contents of an ElasticSearch index?

Is there any way to set the precision of the result when converting a double to string **using `std::to_string()`**? 

The precision of std::to_string(double)

What does `rf` in `rm -rf` in Unix stand for? 

More generally, I have a hard time remembering Unix commands and options because I don&#39;t understand what they stand for. Is there a resource that explain the meaning of these shorthands?

    



What does rf in rm -rf stand for?

<p>What does <code>rf</code> in <code>rm -rf</code> in Unix stand for?</p>
<p>More generally, I have a hard time remembering Unix commands and options because I don't understand what they stand for. Is there a resource that explain the meaning of these shorthands?</p>


I have a fixed-width-field file which I&#39;m trying to sort using the UNIX (Cygwin, in my case) sort utility.

The problem is there is a two-line header at the top of the file which is being sorted to the bottom of the file (as each header line begins with a colon).

Is there a way to tell sort either &quot;pass the first two lines across unsorted&quot; or to specify an ordering which sorts the colon lines to the top - the remaining lines are always start with a 6-digit numeric (which is actually the key I&#39;m sorting on) if that helps.

Example:

    :0:12345
    :1:6:2:3:8:4:2
    010005TSTDOG_FOOD01
    500123TSTMY_RADAR00
    222334NOTALINEOUT01
    477821USASHUTTLES21
    325611LVEANOTHERS00

should sort to:

    :0:12345
    :1:6:2:3:8:4:2
    010005TSTDOG_FOOD01
    222334NOTALINEOUT01
    325611LVEANOTHERS00
    477821USASHUTTLES21
    500123TSTMY_RADAR00


Is there a way to ignore header lines in a UNIX sort?

I need to remove all the blank lines from an input file and write into an output file. Here is my data as below.



    11216,33,1032747,64310,1,0,0,1.878,0,0,0,1,1,1.087,5,1,1,18-JAN-13,000603221321
    
    11216,33,1033196,31300,1,0,0,1.5391,0,0,0,1,1,1.054,5,1,1,18-JAN-13,059762153003
    
    11216,33,1033246,31300,1,0,0,1.5391,0,0,0,1,1,1.054,5,1,1,18-JAN-13,000603211032
    
    11216,33,1033280,31118,1,0,0,1.5513,0,0,0,1,1,1.115,5,1,1,18-JAN-13,055111034001
    
    11216,33,1033287,31118,1,0,0,1.5513,0,0,0,1,1,1.115,5,1,1,18-JAN-13,000378689701
    
    11216,33,1033358,31118,1,0,0,1.5513,0,0,0,1,1,1.115,5,1,1,18-JAN-13,000093737301
    
    11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802041926
    
    11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802041954
    
    11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802049326
    
    11216,33,1035476,37340,1,0,0,1.7046,0,0,0,1,1,1.123,5,1,1,18-JAN-13,045802049383
    
    11216,33,1036985,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000093415580
    
    11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781202001
    
    11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781261305
    
    11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781603955
    
    11216,33,1037003,15151,1,0,0,1.4436,0,0,0,1,1,1.065,5,1,1,18-JAN-13,000781615746


How to remove blank lines from a Unix file

In Ubuntu, I installed PostgreSQL database and created a superuser for the server.

If I forgot the password of the postgresql superuser, how can I reset it (the password) for that user?

I tried uninstalling it and then installing it again but the previously created superuser is retained.

PostgreSQL: Resetting password of PostgreSQL on Ubuntu

On Linux, how can I add a directory to the $PATH so it remains persistent across different sessions?

#### Background

I&#39;m trying to add a directory to my path so it will always be in my Linux path. I&#39;ve tried:

    export PATH=$PATH:/path/to/dir

This works, however each time I exit the terminal and start a new terminal instance, this path is lost, and I need to run the export command again.

How can I do it so this will be set permanently?


How to permanently set $PATH on Linux/Unix

I would like to remove comma `,` at the end of each line in my file. How can I do it other than using substring function in `awk`?

Sample Input:

            SUPPLIER_PROC_ID BIGINT NOT NULL,
        	BTCH_NBR INTEGER NOT NULL,
        	RX_BTCH_SUPPLIER_SEQ_NBR INTEGER NOT NULL,
        	CORRN_ID INTEGER NOT NULL,
        	RX_CNT BYTEINT NOT NULL,
        	DATA_TYP_CD BYTEINT NOT NULL,
        	DATA_PD_CD BYTEINT NOT NULL,
        	CYC_DT DATE NOT NULL,
        	BASE_DT DATE NOT NULL,
        	DATA_LOAD_DT DATE NOT NULL,
        	DATA_DT DATE NOT NULL,
        	SUPPLIER_DATA_SRC_CD BYTEINT NOT NULL,
        	RX_CHNL_CD BYTEINT NOT NULL,
        	MP_IMS_ID INTEGER NOT NULL,
        	MP_LOC_ID NUMERIC(3,0),
        	MP_IMS_ID_ACTN_CD BYTEINT NOT NULL,
        	NPI_ID BIGINT,

How to remove a character at the end of each line in UNIX

Commands follows 


      511  clear
      512  history
      513  history -d 505
      514  history
      515  history -d 507 510 513
      516  history
      517  history -d 509
      518  history
      519  history -d 511
      520  history

I can delete single one by `history -d 511`, but how to delete last 10 commands and in between 10 commands history using single command in shell?

Can we write a bash script and execute for deletion of history?

How to delete history of last 10 commands in shell?

I have a directory full of files with one extension (.txt in this case) that I want to automatically convert to another extension (.md).

Is there an easy terminal one-liner I can use to convert all of the files in this directory to a different file extension?

Or do I need to write a script with a regular expression?



Changing file extensions for all files in a directory on OS X

I want to send IMAP commands via Mac OS X Terminal to server and get response. I can connect to the server using this line: 

    openssl s_client -connect imap.gmail.com:993

And I can successfully login: 

    ? LOGIN m.client2 passwordhere

But all other commands do not work, no response from server. I tried for instance this: 

    ? LIST &quot;&quot; &quot;*&quot;
    ? SELECT INBOX

How to talk to IMAP server in Shell via OpenSSL

I am having a problem installing global node modules and everything I find online says the solve is just adding -g. Which is not the problem. I believe it&#39;s a linking issue or wrong directory issue. 

Here is what I do:

    $ npm install -g express
    npm http GET https://registry.npmjs.org/express
    npm http 304 https://registry.npmjs.org/express
    npm http GET https://registry.npmjs.org/range-parser/0.0.4
    npm http GET https://registry.npmjs.org/mkdirp/0.3.3
    ...downloads correctly
    
    $ express myapp
    bash: express: command not found


However when I run the direct link location to express it works:

       $ /usr/local/share/npm/bin/express myapp
    
       create : myapp
       create : myapp/package.json
       create : myapp/app.js
    ... Builds app correctly



Where the module is: 

    $ which node
    /usr/local/bin/node
    $ node -pe process.execPath
    /usr/local/Cellar/node/0.8.20/bin/node
    $ npm link express
    /Users/bentonrr/Development/Personal/node_modules/express -&gt; /usr/local/share/npm/lib/node_modules/express


In my .bash_profile I have:

    export PATH=/usr/local/bin:$PATH
    export NODE_PATH=/usr/local/lib/node_modules:/usr/local/lib/node

Do I need to change my Node environment to download to correct folder? Is something not linking correctly? I am lost.. 

Thanks!

Other Specs:

    $ node --version
    v0.8.20
    $ npm --version
    1.2.11
    $ brew --version
    0.9.4
    OSX Version 10.8.2



Global Node modules not installing correctly. Command not found

I just made a .c file and compiled it with gcc in the terminal on OS X 10.8.2. 

My syntax was gcc -o `&lt;filename&gt; &lt;sourcefile&gt;` and that was fine. Now I see I have an executable and file `&lt;filename&gt;` tells me as such, but I&#39;m not sure how to actually run it beside double clicking the icon, /lame. When I try running the executable by just typing &lt;filename&gt; I get command not found, but I thought it was executable...?

Thank you. 

EDIT: I&quot;m so stupid, it was just open `&lt;filename&gt;`

Content Type	Original Author	Original Content on Stackoverflow
Question	AdamNYC	View Question on Stackoverflow
Solution 1 - Unix	Gilles Quenot	View Answer on Stackoverflow
Solution 2 - Unix	flavian	View Answer on Stackoverflow
Solution 3 - Unix	vinoth	View Answer on Stackoverflow
Solution 4 - Unix	plasticide	View Answer on Stackoverflow

What does rf in rm -rf stand for?

Unix Problem Overview

Unix Solutions

Solution 1 - Unix

Solution 2 - Unix

Solution 3 - Unix

Solution 4 - Unix

The precision of std::to_string(double)

How can I view the contents of an ElasticSearch index?

Attributions