lazarus's questions

I tested a ffmpeg command to generate thumbnail ffmpeg -y -ss 0 -to 10 -i acb.mp4 -qscale:v 2 -frames:v 1 abc.jpeg on macOS and it worked fine , whereas it gave error for the same command on ubuntu 18.04.2(AWS EC2) for ffmpeg.

error :

Option to (record or transcode stop time) cannot be applied to input url abc.mp4 -- you are trying to apply an input option to an output file or vice versa. Move this option before the file it belongs to.
Error parsing options for input file abc.mp4.
Error opening input files: Invalid argument

I am using AWS EC2 (ubuntu 18.04.2) , used sudo apt install ffmpeg. Can someone please help me with this , if I have to install it in a different way, or if I am missing something here. Thanks in Advance.

I have a python script to run a flask application in ubuntu server. I ssh'ed to the system and ran the flask server with python run.py in debug mode , to see the debug info.

app.run(host='0.0.0.0',port=5000,debug=True)

Somehow I got disconnected to the session as I came to my home network , and when I ssh'ed again I could see that the script is still running( not sure if saying running in background would be correct ).

ubuntu@ip-11-11-11-11:~$ ps -aux | grep python
root       800  0.0  1.4 170820 15096 ?        Ssl  May02   0:00 /usr/bin/python3 /usr/bin/networkd-dispatcher --run-startup-triggers
root       858  0.0  1.5 187636 16100 ?        Ssl  May02   0:00 /usr/bin/python3 /usr/share/unattended-upgrades/unattended-upgrade-shutdown --wait-for-signal
ubuntu   13069  0.0  2.1  58744 21408 pts/1    S+   10:20   0:00 python webhook.py
ubuntu   13071  0.2  2.2 213440 22876 pts/1    Sl+  10:20   0:22 /usr/bin/python /home/ubuntu/webhook.py
ubuntu   13380  0.0  0.1  13136  1008 pts/0    S+   13:13   0:00 grep --color=auto python

and the port number associated with the flask server is open as well.

ubuntu@ip-11-11-11-11:~$ netstat -tunapl | grep LISTEN
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
tcp        0      0 127.0.0.53:53           0.0.0.0:*               LISTEN      -
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -
tcp        0      0 0.0.0.0:5000            0.0.0.0:*               LISTEN      13069/python
tcp6       0      0 :::22                   :::*                    LISTEN      -

I wanted to see the debug info again , so I thought to use fg to bring it into foreground. but there is no output for jobs.

ubuntu@ip-11-11-11-11:~$ jobs
ubuntu@ip-11-11-11-11:~$

I believe it means that python script is a process not job.

Can someone please help me with this , Is there any way I can bring the python script back in the command line. Thanks in Advance.

while going through learn bash the hard way, I found that [ and test are both commands and synonyms, and both are builtin.
As it is a builtin it should not give any error for builtin [ , but I am getting -bash: [: missing `]', Can someone explain me the behavior of builtin here. Thanks in advance.

anupam:Markdown$ which [
/usr/bin/[
anupam:Markdown$ echo $?
0
anupam:Markdown$ which test
/usr/bin/test
anupam:Markdown$ echo $?
0
anupam:Markdown$ builtin test
anupam:Markdown$ echo $?
1
anupam:Markdown$ builtin [
-bash: [: missing `]'
anupam:Markdown$ echo $?
2
anupam:Markdown$ 

While working through two active buffers in Emacs, sum.cpp and template.cpp, I accidentally shut down my laptop (Ubuntu 15.04 (Vivid Vervet)) without closing Emacs, and without saving these two files.

When I restarted the laptop and listed directory content in Emacs by C - x C - f /C++/, I got the following.

What does the line mean after .#sum.cpp?

lrwxrwxrwx  1 anupam anupam   41 Aug  6 00:53 .#sum.cpp -> [email protected]:1438790786

I know Emacs saves the unsaved buffer by # by autosave, but when accessing #sum.cpp why is it showing the following?

file is a symlink to non-existent target?

I just tried a simple menu based shell script to get the public ip of my system. using ( curl ifconfig.me ) .. but I found it behaving differently.

here I tried with:

anupam@JAZZ:~/Desktop$ cat menuui
#
# Script to create simple menus and take action according to that selection
# menu item
#
while :
do
    clear
    echo "___________________________________"
    echo "Main Menu"
    echo "___________________________________"
    echo "[1] Show Today's date/time"
    echo "[2] Show files in current directory"
    echo "[3] Show calendar"
    echo "[4] Start a calculator"
    echo "[5] Start editor to write letters"
    echo "[6] Show your public ip"
    echo "[7] Exit/Stop"
    echo "===================================="
    echo -n "Enter your menu choice[1-5]:"
    read yourch
    case $yourch in
    1) echo "Today is `date` ,press a key..." ; read ;;
    2) echo "Files in `pwd` "; ls -l;echo "Press a key..."; read;;
    3) cal; echo "Press a key..." ; read ;;
    4) bc;;
        5) vi;;
        6) echo "Your public ip is `curl ifconfig.me`";;
    7) exit 0 ;;
    *) echo "Opps!!! Please select choices 1,2,3,4 or 5";
    echo "Press a key...";read;;
    esac
done

then I executed it...

which is not I expected..How could I resolve this??

I tried ss command to know the status of sockets in my system (ubuntu 14.10 ),

$ ss
tcp    ESTAB      0      0         192.168.1.10:51492    74.125.236.200:https   
tcp    ESTAB      0      0         192.168.1.10:45436      184.24.9.251:http    
tcp    ESTAB      0      0         192.168.1.10:33349     74.125.236.68:https   
tcp    ESTAB      0      0         192.168.1.10:45285     74.125.236.34:https   
tcp    ESTAB      0      0         192.168.1.10:52029    74.125.169.216:https   
tcp    ESTAB      0      0         192.168.1.10:49125      184.24.9.251:https   
tcp    ESTAB      0      0         192.168.1.10:49340      74.125.68.94:https   
tcp    ESTAB      0      0         192.168.1.10:47748     74.125.236.65:https   
tcp    ESTAB      0      0         192.168.1.10:32845     199.59.150.46:https   
tcp    ESTAB      0      0         192.168.1.10:34511     103.20.92.129:https   
tcp    ESTAB      0      0         192.168.1.10:43233    74.125.200.188:5228    
tcp    ESTAB      0      0         192.168.1.10:52208    74.125.169.216:https   
tcp    ESTAB      0      0         192.168.1.10:41742    184.87.213.124:http    
tcp    ESTAB      0      0         192.168.1.10:43939     74.125.68.147:https   
tcp    ESTAB      0      0         192.168.1.10:36935     74.125.236.90:http    
tcp    ESTAB      0      0         192.168.1.10:48165     74.125.236.33:https   
tcp    ESTAB      0      0         192.168.1.10:41456     74.125.236.34:http    
tcp    ESTAB      0      0         192.168.1.10:40549     74.125.236.90:https   
tcp    ESTAB      0      0         192.168.1.10:37934     122.175.190.8:http    
tcp    ESTAB      0      0         192.168.1.10:44557      31.13.79.112:https   
tcp    ESTAB      0      0         192.168.1.10:49879     74.125.236.43:https   
tcp    ESTAB      0      0         192.168.1.10:54648     23.34.240.214:http    
tcp    ESTAB      0      0         192.168.1.10:60101     74.125.236.67:https   
tcp    ESTAB      0      0         192.168.1.10:60836   108.160.165.173:http    

and here in one of output I got

tcp    ESTAB      0      0         192.168.1.10:43233    74.125.200.188:5228 

then I tried nslookup ,I got

anupam@JAZZ:~$ nslookup 74.125.200.188
Server:     127.0.1.1
Address:    127.0.1.1#53

Non-authoritative answer:
188.200.125.74.in-addr.arpa name = sa-in-f188.1e100.net.

Authoritative answers can be found from:

I am not getting 188.200.125.74.in-addr.arpa name = sa-in-f188.1e100.net.part here ,,

then I tried netstat to know the PID associated with this..

$ netstat -natp
tcp        0      0 192.168.1.10:60081      74.125.236.73:443       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:54746      74.125.236.199:80       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:32845      199.59.150.46:443       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:55852      74.125.236.67:80        ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:43119      198.252.206.25:443      ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:43233      74.125.200.188:5228     ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:41044      74.125.130.104:443      ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:56479      74.125.236.196:443      ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:48165      74.125.236.33:443       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:35692      74.125.236.74:443       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:60101      74.125.236.67:443       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:60836      108.160.165.173:80      ESTABLISHED 2919/dropbox    
tcp        0      0 192.168.1.10:52425      74.125.236.201:443      ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:60058      74.125.236.73:443       ESTABLISHED 5141/chromium-brows
tcp        0      0 192.168.1.10:40360      74.125.130.94:443       ESTABLISHED 5141/chromium-brows

Here I found that It was thread of PID 5141 ,in chromium browser ,,

My question is as browsers are just user interface for http or https protocol implementation to exchange html pages ,, how any thread of it can use port no other than 80 or 443..(43233 here) ??

I have installed an app on my android device which makes it a ftp or https server by fixing a port number for listening and username and password in case of ftp server.

I have successfully tried the ftp from android device as a server and my ubuntu 14.10 desktop as a client(by filezilla),both having local ip's ,under the same Wifi connection.

But when I tried for https server on my android device by making it to listen on port no.50345 and having local ip address of 192.168.1.7 . and started the server.

I switched to my ubuntu desktop in the same home network and changed the proxy setting to ip 192.168.1.7 (android device) and port no. to 50345(port no on which the https server is listening) , and on the address bar I typed

https://192.168.1.7:50345

but it's not working and showing an error on my android app log file:

[jazz]-Listening for connections
[jazz]-192.168.1.10-Error 43:CONNECT method not supported

well 192.168.1.10 is my ubuntu system's ip Can someone tell me why is this so?? It worked well with ftp but not so with https?

while reading about file creation in linux I got :

Another way to create a file at the terminal is cat > <filename> << EOF. A new file is created and you can type the required input. To exit, enter EOF at the beginning of a line.

so I tried this on my shell prompt

$ cat > test1.txt <<ABC
> This is just a test file.
> ABC
$ cat test1.txt
This is just a test file.

here when I typed ABC(it could be anything - just for matching pattern) .in the newline it worked(accepted as it would have done in case of ctrl + C),but when I tried

$ cat >> test1.txt <<ABC
> just for a trial
> though ABC
> it didnt worked.
> ABC
$ cat test1.txt
This is just a test file.
just for a trial
though ABC
it didnt worked.
$ 

doing this , it only worked in the newline. Does it mean that << works for newline,

And what's going on inside cat> test1.txt <<ABC exactly ??

While reading about Linux, especially about sudo, I got:

A message such as the following would appear in a system log file (usually /var/log/secure) when trying to execute sudo bash without successfully authenticating the user:

authentication failure; logname=op uid=0 euid=0 tty=/dev/pts/6 ruser=op rhost= user=op
conversation failed
auth could not identify password for [op]
op : 1 incorrect password attempt ;
TTY=pts/6 ; PWD=/var/log ; USER=root ; COMMAND=/bin/bash

Then I tried it in my shell prompt:

anupam@JAZZ:~$ sudo bash
[sudo] password for anupam: 
root@JAZZ:~# 

then when I looked for /var/log/secure, it was not there

anupam@JAZZ:~$ more /var/log/secure
/var/log/secure: No such file or directory
anupam@JAZZ:~$ ls /var/log
alternatives.log       auth.log         dmesg           gpu-manager.log  mysql.log              pm-suspend.log.2.gz  upstart
alternatives.log.1     auth.log.1       dmesg.0         hp               mysql.log.1.gz         samba                wtmp
alternatives.log.2.gz  auth.log.2.gz    dmesg.1.gz      installer        mysql.log.2.gz         speech-dispatcher    wtmp.1
apache2                auth.log.3.gz    dmesg.2.gz      jetty            mysql.log.3.gz         syslog               Xorg.0.log
apport.log             auth.log.4.gz    dmesg.3.gz      kern.log         mysql.log.4.gz         syslog.1             Xorg.0.log.old
apport.log.1           boot.log         dmesg.4.gz      kern.log.1       mysql.log.5.gz         syslog.2.gz          Xorg.1.log
apport.log.2.gz        bootstrap.log    dpkg.log        kern.log.2.gz    mysql.log.6.gz         syslog.3.gz          Xorg.1.log.old
apport.log.3.gz        btmp             dpkg.log.1      kern.log.3.gz    mysql.log.7.gz         syslog.4.gz
apport.log.4.gz        btmp.1           dpkg.log.2.gz   kern.log.4.gz    pm-powersave.log       syslog.5.gz
apport.log.5.gz        ConsoleKit       faillog         lastlog          pm-powersave.log.1     syslog.6.gz
apport.log.6.gz        cups             fontconfig.log  lightdm          pm-powersave.log.2.gz  syslog.7.gz
apport.log.7.gz        dbconfig-common  fsck            mysql            pm-suspend.log         udev
apt                    dist-upgrade     gdm             mysql.err        pm-suspend.log.1       unattended-upgrades

Is there any alternative for /var/log/secure in my system?

while reading about linux I got :

By default, variables created within a script are only available to the current shell; child processes (sub-shells) will not have access to values that have been set or modified. Allowing child processes to see the values, requires use of the export command.

I tried to find about subshells then I came across Are there any command to see how processes are working?, and I found ltrace could be used for that, when I searched for how to use ltrace or strace, I found that PID is required attribute for that.

now, If I want to know the PID for $ cp file1 file2 ,how would I do that?? so that I can use ltrace to it??

While looking for a solution for the Hungarian problem, I found this GitHub link.

I went through the readme.md file and I performed everything described there. After copying hungarian.so into my working directory, when I tried to compile hungarian.cpp using make hungarian, I got this output:

anupam@JAZZ:~/Python/hungarian-master$ make hungarian
g++     hungarian.cpp   -o hungarian
hungarian.cpp:7:20: fatal error: Python.h: No such file or directory
 #include "Python.h"
                    ^
compilation terminated.
make: *** [hungarian] Error 1

I found this related question on Stack Overflow, but the answer didn't work for me.

I am very new to GitHub I don't know how to add modules on g++. Can someone help me with that, and what to do next?

While reading about Linux, I got a $netstat -tulpn to find out which process is listening Upon a port. I got:

anupam@JAZZ:~$ sudo netstat -tulpn
[sudo] password for anupam: 
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 127.0.1.1:53            0.0.0.0:*               LISTEN      1827/dnsmasq    
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      1992/cupsd      
tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      976/mysqld      
tcp6       0      0 :::80                   :::*                    LISTEN      1342/apache2    
tcp6       0      0 ::1:631                 :::*                    LISTEN      1992/cupsd      
tcp6       0      0 :::3689                 :::*                    LISTEN      2582/rhythmbox  
udp        0      0 0.0.0.0:631             0.0.0.0:*                           943/cups-browsed
udp        0      0 0.0.0.0:37759           0.0.0.0:*                           697/avahi-daemon: r
udp        0      0 0.0.0.0:58502           0.0.0.0:*                           1822/dhclient   
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           3039/chromium-brows
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           697/avahi-daemon: r
udp        0      0 127.0.1.1:53            0.0.0.0:*                           1827/dnsmasq    
udp        0      0 0.0.0.0:68              0.0.0.0:*                           1822/dhclient   
udp6       0      0 :::5353                 :::*                                697/avahi-daemon: r
udp6       0      0 :::44452                :::*                                697/avahi-daemon: r
udp6       0      0 :::16540                :::*                                1822/dhclient   

There is a single PID for googleChromium, while I have opened multiple windows and multiple tabs in it. I read that chromium uses processes rather than threads http://blog.chromium.org/2008/09/multi-process-architecture.html, as port numbers are used for application to application connection (so I understand that there is a single PID for chromium). But what about PIDs for other processes associated with Chromium??

While reading about Linux, I got a $ who -a, so before trying that I logged into three of my text terminals (tty1,tty2,tty3) respectively,, and then I came back to X-window (Ctrl + Alt +f7),, then I tried:-

$ who
anupam   tty2         2014-09-20 16:19
anupam   tty3         2014-09-20 16:20
anupam   tty1         2014-09-20 16:18
anupam   :0           2014-09-20 16:14 (:0)
anupam   pts/0        2014-09-20 16:21 (:0)
$ whoami
anupam
$ who -a
           system boot  2014-09-20 16:13
           run-level 2  2014-09-20 16:13
LOGIN      tty4         2014-09-20 16:13               736 id=4
LOGIN      tty5         2014-09-20 16:13               740 id=5
anupam   - tty2         2014-09-20 16:19 00:01        3200
anupam   - tty3         2014-09-20 16:20   .          3346
LOGIN      tty6         2014-09-20 16:13               752 id=6
anupam   - tty1         2014-09-20 16:18 00:02        3044
anupam   ? :0           2014-09-20 16:14   ?          1835 (:0)
anupam   + pts/0        2014-09-20 16:21   .          3455 (:0)
$ 

I am not getting some terms in second attribute (- tty2,-tty 3,-tty1i [why - is there in front of them?]) ?:0 (I guess it is indicating my X-window startup [why is there a ? before :0?]), and values at fourth attribute [00:01, ., 00:02, ?, .]?

I tried to look at $ man who -a, but I didn't got these explanation.

when I tried $ mount command on my system (14.04 LTS), I found some of the results like...

none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)

I am not getting this file system or device node none is mounted on multiple mount points like(/sys/fs/cgroup ,/sys/kernel/security, /run/shm etc)..

does it infer there is nothing or is it a file system or device node..?

while reading about linux I got the following..

Typing mount without any arguments will show all presently mounted filesystems.

when I tried this on my system , I got..

anupam@JAZZ:~$ mount
/dev/sda5 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)
selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
systemd on /sys/fs/cgroup/systemd type cgroup (rw,noexec,nosuid,nodev,none,name=systemd)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=anupam)
/dev/sda2 on /media/anupam/1C44CC1044CBEA9A type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096)

well, I get that everything before on is a device node and after that is a mount point ,but I am not getting some of the types.

Are these types of file systems like ext4 ,ext3 , btrfs ,xfs - because at /dev/sda5 its type is ext4(which is file system for linux), but for /dev/sda2(which is C:\ of windows 8) it is showing fuseblk(but file system for it is ntfs) .

and `parameters(rw,noexec,nosuid,nodev etc. ) related to these types ,, can someone please give me a quick reference to get all of these,

While reading about Linux I got the following:

touch provides several options, but here is one of interest:

The -t option allows you to set the date and time stamp of the file. To set the time stamp to a specific time:

$ touch -t 03201600 myfile

This sets the file, myfile's, time stamp to 4 p.m., March 20th (03 20 1600).

Here, I am not getting the logic behind 03201600 --> 4pm, March 20th.

while reading about linux file searching I got the following...

To search for files using the * wildcard, replace the unknown string with *, e.g. if you remember only that the extension was .out, type ls *.out

and when I tried the following command on system(ubuntu 14.04 LTS) ..I got

anupam@JAZZ:~$ ls  *.bash* 

ls: cannot access  *.bash* : No such file or directory

anupam@JAZZ:~$ ls  .bash*

.bash_history   .bash_logout  .bash_profile  .bashrc

anupam@JAZZ:~$

in the first case why it is showing No such directory ( *.bash* ) and in next case its showing the files ( .bash* )

I am new to this flavor, and according to my automata theory classes (*) means any combination of strings including epsilon(empty),,So why the results are different in both the cases....?

While reading about Ubuntu I found the following statement.....

If the display manager is not started by default in the default runlevel, you can start X a different way, after logging on to a text-mode console, by running startx from the command line.

What does it mean to be a default runlevel? And when I tried this on my terminal I got this:

anupam@JAZZ:~$ startx

X: user not authorized to run the X server, aborting.
xinit: giving up
xinit: unable to connect to X server: Connection refused
xinit: server error

I came across the following statement ..

When booting Linux, the boot loader is responsible for loading the kernel image and the initial RAM disk (which contains some critical files and device drivers needed to start the system) into memory.

what does it mean to load a kernal image and initial RAM disk,Is there any command or application by which I can see them logically where they are ?

When I entered the -al attribute with the ls command, I got the following:

anupam@JAZZ:~/blog$ ls -al
total 76
drwxrwxr-x 13 anupam anupam 4096 Aug 28 21:45 .
drwxr-xr-x 34 anupam anupam 4096 Aug 28 20:52 ..
drwxrwxr-x  8 anupam anupam 4096 Aug 28 12:19 app
drwxr-xr-x  2 anupam anupam 4096 Aug 28 12:19 bin
drwxrwxr-x  5 anupam anupam 4096 Aug 28 12:19 config
-rw-rw-r--  1 anupam anupam  154 Aug 28 12:19 config.ru
drwxrwxr-x  3 anupam anupam 4096 Aug 28 12:37 db
-rw-rw-r--  1 anupam anupam 1339 Aug 28 12:19 Gemfile
-rw-rw-r--  1 anupam anupam 2871 Aug 28 12:19 Gemfile.lock
drwxrwxr-x  7 anupam anupam 4096 Aug 28 21:45 .git
-rw-rw-r--  1 anupam anupam  466 Aug 28 12:19 .gitignore
drwxrwxr-x  4 anupam anupam 4096 Aug 28 12:19 lib
drwxrwxr-x  2 anupam anupam 4096 Aug 28 12:29 log
drwxrwxr-x  2 anupam anupam 4096 Aug 28 12:19 public
-rw-rw-r--  1 anupam anupam  249 Aug 28 12:19 Rakefile
-rw-rw-r--  1 anupam anupam  478 Aug 28 12:19 README.rdoc
drwxrwxr-x  8 anupam anupam 4096 Aug 28 12:19 test
drwxrwxr-x  6 anupam anupam 4096 Aug 28 12:33 tmp
drwxrwxr-x  3 anupam anupam 4096 Aug 28 12:19 vendor

What does each column mean, and what does the total 76 signify here?