Question on file owner name representation Post: 302425559

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Top Forums Shell Programming and Scripting Question on file owner name representation Post 302425559 by Corona688 on Friday 28th of May 2010 12:25:54 PM

05-28-2010

Registered User

Quote:

Originally Posted by Arunprasad

I thought the same but in my case, all user s are LDAP and not maintained locally. So how system determines that this user has been deleted and let represent the userid as number. And for your information, still many user directories/files are showing properly with userid/owner name in its properties.

Thanks a lot for your time! Please advise.

It's abstracted behind the getpwent() call and its related calls, looks like:

Code:

GETPWENT(3)                Linux Programmer's Manual               GETPWENT(3)



NAME
       getpwent, setpwent, endpwent - get password file entry

SYNOPSIS
       #include <sys/types.h>
       #include <pwd.h>

       struct passwd *getpwent(void);

       void setpwent(void);

       void endpwent(void);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getpwent(), setpwent(), endpwent(): _BSD_SOURCE || _SVID_SOURCE ||
       _XOPEN_SOURCE > = 500

DESCRIPTION
       The getpwent() function returns a pointer to a structure containing the
       broken-out  fields  of  a  record from the password database (e.g., the
       local password file /etc/passwd, NIS, and LDAP).  The first time it  is
       called  it  returns  the first entry; thereafter, it returns successive
       entries.

...

So ls doesn't reach in and grab login names from /etc/passwd manually, it just calls getpwent() from glibc, which is capable of getting login info from any valid sources. Finding no corresponding UID in either, ls just prints the UID/GID.

Didn't know getpwent() did that. That's a pretty good reason to use these functions instead of just parsing /etc/passwd yourself!

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LEARN ABOUT DEBIAN

paps

PAPS(1) 						      General Commands Manual							   PAPS(1)

NAME

       paps - UTF-8 to PostScript converter using Pango

SYNOPSIS

       paps [options] files...

DESCRIPTION

       paps reads a UTF-8 encoded file and generates a PostScript language rendering of the file. The rendering is done by creating outline curves
       through the pango ft2 backend.

OPTIONS

       These programs follow the usual GNU command line syntax, with long options starting with  two  dashes  (`-').   A  summary  of  options	is
       included below.

       --landscape
	      Landscape output. Default is portrait.

       --columns=cl
	      Number of columns output. Default is 1.
	      Please notice this option isn't related to the terminal length as in a "80 culums terminal".

       --font=desc
	      Set the font description. Default is Monospace 12.

       --rtl  Do right to left (RTL) layout.

       --paper ps
	      Choose paper size. Known paper sizes are legal, letter and A4. Default is A4.

       Postscript points
	      Each postscript point equals to 1/72 of an inch. 36 points are 1/2 of an inch.

       --bottom-margin=bm
	      Set bottom margin. Default is 36 postscript points.

       --top-margin=tm
	      Set top margin. Default is 36 postscript points.

       --left-margin=lm
	      Set left margin. Default is 36 postscript points.

       --right-margin=rm
	      Set right margin. Default is 36 postscript points.

       --gutter-width=gw
	      Set gutter width. Default is 40 postscript points.

       --help Show summary of options.

       --header
	      Draw page header for each page.

       --markup
	      Interpret the text as pango markup.

       --lpi  Set the lines per inch. This determines the line spacing.

       --cpi  Set the characters per inch. This is an alternative method of specifying the font size.

       --stretch-chars
	      Indicates  that  characters  should be stretched in the y-direction to fill up their vertical space. This is similar to the texttops
	      behaviour.

AUTHOR

       paps was written by Dov Grobgeld <dov.grobgeld@gmail.com>.

       This manual page was written by Lior Kaplan <kaplan@debian.org>, for the Debian project (but may be used by others).

								  April  17, 2006							   PAPS(1)

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