[linux] mazanie riadkov v subore a jazyk C

[Marcel Telka]

On Thu, Jul 04, 2002 at 12:30:30PM +0200, peter Fodrek wrote:
> 
> 
> 
> 
> 
> Od: Ondrej Jombik [SMTP:nepto na pobox.sk]
> >Odesláno: 3. júl 2002 23:40
> >Komu: linux na lists.linux.sk
> >Pøedmìt: RE: [linux] mazanie riadkov v subore a jazyk C
> 
> 
> >> >    Robim nejaky program v C-cku a kedze nie som nejaky skuseny
> developer
> >> > mam mozno pre niekoho lamersku otazku ;-). Potrebujem mazat riadky v
> >> > otvorenom subore napr. odstranit uzivatela z passwd suboru. Akym
> sposobom
> >> > Aky sposob sa pouziva na taketo veci?
> >> Ani to co si napisal nie je hovadina, ale skor by som to robil tak, ze by
> >> som si cely file nacital ako dynamicke pole a zaznamenal si do dalsieho
> >> dynamickeho pola , ktore riadky mam vynechat a pri zapise prislusne prvky
> >
> >Staci zacat zapisovat od miesta, kde sa nachadza zaciatok riadku, ktory
> chcete vymazat.
> 
> Nepto, ale vies ako je nebezpecne robit s fseek a ftell.... Nieco zmrvis a
> mas po file.... a tu islo o passwd....
> Samozrejme ak to mas vyskusane tak potom je to super riesenie, len neviem co
> sa stane po fclose, pre fopen(filename,"w") , ak bol subor dlhsi, logicky by
> mal zapisat EOF a potom  udaje do INODE, ale nikdy nevies ci ho neda na
> koniec citaneho file...
> Toto treba otestovat. Inak mas paravdu...

Kedze sa jedna o /etc/passwd nebolo by lepsie pouzit nieco ako libuser?


$ rpm -qi libuser
Name        : libuser                      Relocations: (not relocateable)
Version     : 0.50.2                            Vendor: Red Hat, Inc.
Release     : 1                             Build Date: Tue 16 Apr 2002 10:58:20 PM CEST
Install date: Wed 26 Jun 2002 01:58:11 PM CEST      Build Host: porky.devel.redhat.com
Group       : System Environment/Base       Source RPM: libuser-0.50.2-1.src.rpm
Size        : 847365                           License: LGPL
Packager    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>
Summary     : A user and group account administration library.
Description :
The libuser library implements a standardized interface for manipulating
and administering user and group accounts.  The library uses pluggable
back-ends to interface to its data sources.

Sample applications modeled after those included with the shadow password
suite are included.


Ahoj.

-- 
+-------------------------------------------+
| Marcel Telka   e-mail:   marcel na telka.sk  |
|                homepage: http://telka.sk/ |
|                jabber:   marcel na jabber.sk |
+-------------------------------------------+