file modification date

[phazei]

When a file is saved or modified in some manner, the modified date is changed. I have 2 questions, is that taken care of automatically by the os when a program changes it?

And when a file is saved, sometimes it's a large file or it takes a while to save. In gedit even in a tiny text file, it says 'saving' at the bottom for a few seconds. Is the file modification date updated at the beginning or end of the write?

[Lakshmipathi]

I don't understand your question exactly,but here is more info:

time changes are done to file inode by OS (the kernel). Date modification will be done while writing meta data back to disk.

does that answer your question?

[phazei]

Ok, then I'm asking, is the date modification done before or after the meta data has been written?

If it's a large piece is the meta data split into pieces? If so, is the date update initiated with each piece or at the start or at the end?

(I guess this next question could be derived from the answers of above)
If a program checks and the date has been updated, does that mean the file is not being written to anymore (assuming another process doesn't initiate another write to the file in the in term)?

[Lakshmipathi]

is the date modification done before or after the meta data has been written?

Time stamps will be found in File's Meta data (which is inode).
Data blocks refers to file contents.Kernel will write the file contents first (that's Data
block ) and then update the inode.

If a program checks and the date has been updated, does that mean the file is not being written to anymore

inode update will be done once file contents are stored in disk. If the file is opened by a single process,then updation is said to be over/completed.

[phazei]

Thanks
That answers it all.