Sfrgttk

Can you run a ground wire from stove directly to ground pole in the ground

School performs periodic password audits. Is my password compromised?

Iron deposits mined from under the city

Why do phishing e-mails use faked e-mail addresses instead of the real one?

What is Tony Stark injecting into himself in Iron Man 3?

Giving a talk in my old university, how prominently should I tell students my salary?

Rationale to prefer local variables over instance variables?

In the world of The Matrix, what is "popping"?

When to use the term transposed instead of modulation?

Affine transformation of circular arc in 3D

What is better: yes / no radio, or simple checkbox?

PTIJ: Aliyot for the deceased

Why would the IRS ask for birth certificates or even audit a small tax return?

Create chunks from an array

Naming Characters after Friends/Family

Problems with rounding giving too many digits

How to make sure I'm assertive enough in contact with subordinates?

Does the US political system, in principle, allow for a no-party system?

The need of reserving one's ability in job interviews

“I had a flat in the centre of town, but I didn’t like living there, so …”

How spaceships determine each other's mass in space?

The (Easy) Road to Code

Infinitive vs Gerund

What is the oldest European royal house?

Why would /etc/passwd be used every time someone executes `ls -l` command?

Why root's password change doesn't require old passwordFreeBSD create user without utility?Difference between ! vs !! vs * in /etc/shadowConditionally unlock a password, on a read-only filesystemWhat is the default SHA512 salt used in passwd and for the hash stored in the shadow file?Why the “ passwd ” command give the root shell without password?useradd command truncates the password mentioned with -p optionNo users can log inWhy passwd prohibits me from setting “simple” password?I want a normal user to change it's own password

4

Read from APUE, just feel curious:

The password file is used every time a user logs in to a
UNIX system and every time someone executes an ls -l command.

ls passwd

share|improve this question

edited 1 hour ago

Olorin

3,8681721

asked 2 hours ago

RickRick

1335

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  FYI I try strace ls -l later on, I see a openat(AT_FDCWD, "/etc/passwd", O_RDONLY|O_CLOEXEC) = 4 statement.
  
  – Rick
  9 mins ago
  
  
  

  
  
  
  

add a comment | 

4

Read from APUE, just feel curious:

The password file is used every time a user logs in to a
UNIX system and every time someone executes an ls -l command.

ls passwd

share|improve this question

edited 1 hour ago

Olorin

3,8681721

asked 2 hours ago

RickRick

1335

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  FYI I try strace ls -l later on, I see a openat(AT_FDCWD, "/etc/passwd", O_RDONLY|O_CLOEXEC) = 4 statement.
  
  – Rick
  9 mins ago
  
  
  

  
  
  
  

add a comment | 

Read from APUE, just feel curious:

The password file is used every time a user logs in to a
UNIX system and every time someone executes an ls -l command.

ls passwd

share|improve this question

edited 1 hour ago

Olorin

3,8681721

asked 2 hours ago

RickRick

1335

share|improve this question

edited 1 hour ago

Olorin

3,8681721

asked 2 hours ago

RickRick

1335

share|improve this question

edited 1 hour ago

Olorin

3,8681721

asked 2 hours ago

RickRick

1335

edited 1 hour ago

Olorin

3,8681721

edited 1 hour ago

Olorin

3,8681721

asked 2 hours ago

RickRick

1335

asked 2 hours ago

RickRick

1335

1 Answer
1

active

oldest

votes

5

The file-system directly associates the numerical UID (User ID) and GID (Group ID) values with the file, not the user name and group name (which are strings). So the ls -l command (and any other command that displays the user and group owner of a file) need to get the user and group names from somewhere. The /etc/passwd file is one such source (probably the original and most common source). The manual bears this out - from PASSWD (5) (i.e. the man page for the /etc/passwd file):

many utilities, like ls(1) use it to map user IDs to usernames

share|improve this answer

edited 2 hours ago

answered 2 hours ago

igaligal

5,3711234

add a comment | 

Your Answer

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "106"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f505069%2fwhy-would-etc-passwd-be-used-every-time-someone-executes-ls-l-command%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

5

The file-system directly associates the numerical UID (User ID) and GID (Group ID) values with the file, not the user name and group name (which are strings). So the ls -l command (and any other command that displays the user and group owner of a file) need to get the user and group names from somewhere. The /etc/passwd file is one such source (probably the original and most common source). The manual bears this out - from PASSWD (5) (i.e. the man page for the /etc/passwd file):

many utilities, like ls(1) use it to map user IDs to usernames

share|improve this answer

edited 2 hours ago

answered 2 hours ago

igaligal

5,3711234

add a comment | 

5

The file-system directly associates the numerical UID (User ID) and GID (Group ID) values with the file, not the user name and group name (which are strings). So the ls -l command (and any other command that displays the user and group owner of a file) need to get the user and group names from somewhere. The /etc/passwd file is one such source (probably the original and most common source). The manual bears this out - from PASSWD (5) (i.e. the man page for the /etc/passwd file):

many utilities, like ls(1) use it to map user IDs to usernames

share|improve this answer

edited 2 hours ago

answered 2 hours ago

igaligal

5,3711234

add a comment | 

The file-system directly associates the numerical UID (User ID) and GID (Group ID) values with the file, not the user name and group name (which are strings). So the ls -l command (and any other command that displays the user and group owner of a file) need to get the user and group names from somewhere. The /etc/passwd file is one such source (probably the original and most common source). The manual bears this out - from PASSWD (5) (i.e. the man page for the /etc/passwd file):

many utilities, like ls(1) use it to map user IDs to usernames

share|improve this answer

edited 2 hours ago

answered 2 hours ago

igaligal

5,3711234

share|improve this answer

edited 2 hours ago

answered 2 hours ago

igaligal

5,3711234

answered 2 hours ago

igaligal

5,3711234

answered 2 hours ago

igaligal

5,3711234