Why updating atime doesn't update ctime?


Login or Register for Dates, Times and to Reply

 
Thread Tools Search this Thread
Top Forums UNIX for Advanced & Expert Users Why updating atime doesn't update ctime?
# 1  
Why updating atime doesn't update ctime?

Hi,

ctime is the inode change time. If reading a file, its atime will be updated, which should cause inode member i_atime changed, which is an inode change. So ctime should also be updated. But if I try to ls a directory on redhat, only the directory atime gets updated, not ctime. Why?

THANKS!
# 2  
inodes are data about a file in a given filesystem. What is stored in an inode is system dependent, there is no standard.

POSIX compliant systems specifically update ctime (where ever it is kept) only with a change involving:
1. file creation
2. file permissions
3. acl changes
Otherwise ctime would have no meaning because it would be identical to atime. Every read access would update the file status time as well as the access time


Check out the utime() call on your system, or google for 'opengroup.org: utime'. utime() does update ctime.
# 3  
you are semantically right, but ...

1) what you just said about 'atime/read' would also apply to 'mtime/write' ;

2) if you consider "inode"-change meaning "owner/group/mode"-change, then the results shall match the text better, don't you think ?

and please (for the sake of goodness) consider that the 'original' description you mentioned was written about 3 decades ago, and was not 'revised' ever since ;

hth

good luck, and success.
alexandre botao

Moderator's Comments:
Mod Comment Please refrain from posting your website as advertisement in your footer - you got 2 expired infractions for this already... Check your PMs.

Last edited by zaxxon; 12-05-2011 at 07:52 AM.. Reason: removing url of OPs website
Login or Register for Dates, Times and to Reply

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #602
Difficulty: Medium
MySQL 8.0 incorporates a transactional data dictionary that stores information about database objects.
True or False?

9 More Discussions You Might Find Interesting

1. Solaris

Zfs - what does atime update?

It is widely documented that on zfs atime updates the access time on zfs. Where is the access time updated on Solaris 11.2? If I create file atimetest.txt under rpool/export/home: # zfs list rpool/export/home NAME USED AVAIL REFER MOUNTPOINT rpool/export/home 13.3G ... (5 Replies)
Discussion started by: jabberwocky
5 Replies

2. AIX

AIX 6.1 TL8 update : bos.aso doesn't install.

Hello. An update of TL from TL7 to TL8 is ending with errors : Requisite Failures ------------------ SELECTED FILESETS: The following is a list of filesets that you asked to install. They cannot be installed until all of their requisite filesets are also installed. See subsequent... (4 Replies)
Discussion started by: stephnane
4 Replies

3. UNIX for Dummies Questions & Answers

-atime not working as expected

I need to sort through a volume that contains video files by access time and delete files that have not been accessed over x days. I have to use the access time as video files are originals that do not get modified, just read Testing commands on a local test folder... $ date Wed Sep 28... (10 Replies)
Discussion started by: canon273
10 Replies

4. Shell Programming and Scripting

Makefile doesn't update $< variable

Hello guys, I could use advise from more experienced guys about my Makefile. In short, the problem with my Makefile is that $< doesnt change inside my rule. Here is my Makefile: # Makefile for CORE CC = gcc.exe AS = as.exe AR = ar.exe INCLUDE = \ -I../lib/tomcrypt/inc \... (1 Reply)
Discussion started by: Kodreanu
1 Replies

5. UNIX for Advanced & Expert Users

mtime VS atime VS ctime

hi, in trying to maintain your directories, one needs to do some housekeeping like removing old files. the tool "find" comes in handy. but how would you decide which option to use when it comes to, say, deleting files that are older than 5 days? mtime - last modified atime - last accessed... (4 Replies)
Discussion started by: pinoy43v3r
4 Replies

6. Shell Programming and Scripting

how to find ot ctime , mtime ,atime

Can any one tell me how to find out ctime , mtime ,atime for a file/directory on unix. Cheers, Nilesh (5 Replies)
Discussion started by: nilesrex
5 Replies

7. Shell Programming and Scripting

awk updating one file with another, comparing, updating

Hello, I read and search through this wonderful forum and tried different approaches but it seems I lack some knowledge and neurones ^^ Here is what I'm trying to achieve : file1: test filea 3495; test fileb 4578; test filec 7689; test filey 9978; test filez 12300; file2: test filea... (11 Replies)
Discussion started by: mecano
11 Replies

8. Tips and Tutorials

mtime, ctime, and atime

Unix keeps 3 timestamps for each file: mtime, ctime, and atime. Most people seem to understand atime (access time), it is when the file was last read. There does seem to be some confusion between mtime and ctime though. ctime is the inode change time while mtime is the file modification time. ... (2 Replies)
Discussion started by: Perderabo
2 Replies

9. UNIX for Dummies Questions & Answers

atime, ctime, mtime somewhere along csize..

i have used all forms of the unix find command.. and right now this is the only command i can think of that might have this option..: if i use mtime i am looking at a time interval.. but if i wanted to find out intervals of access, change and modification according to when a file changed size... (4 Replies)
Discussion started by: moxxx68
4 Replies

Featured Tech Videos