UNIX for Advanced & Expert Users

There r 2 servers. Lets call them S1 and S2..

S1 is OSF1 and S2 is SunOS..

One directory of S2 is mounted on S1. say abc/xyz

There is one application which continuously put xml files in that directory (on S2).

If we give command “ls -lrt” on S2 it gives proper output.. (i.e. gives list of all files, sorted on time with reverse order)

But if we give same command on S1, it doesn't work. (coz this one is lowest version of UNIX).



We have shell script which runs on S1. which takes these files, reads it and stores data into oracle. Everything is running fine.

But we need to process all the files in sequence. For that we need to list out all those files in sorted order of time...


below is the command which we are using to get files listed in FIFO manner, when tried to run on OSF1:
These files are created at the same time. FILE_WOIR.7229373.txt is oldest file and FILE_WOC.7229343.txt is latest among the listed below.

S1> ls -lt
-rw-r--r-- 1 3130 10 68 Mar 26 11:45 FILE_WOC.7229343.txt
-rw-r--r-- 1 3130 10 68 Mar 26 11:45 FILE_WOC.7229349.txt
-rw-r--r-- 1 3130 10 68 Mar 26 11:45 FILE_WOC.7229369.txt
-rw-r--r-- 1 3130 10 69 Mar 26 11:45 FILE_WOIR.7229345.txt
-rw-r--r-- 1 3130 10 69 Mar 26 11:45 FILE_WOIR.7229351.txt
-rw-r--r-- 1 3130 10 69 Mar 26 11:45 FILE_WOIR.7229373.txt

Now after using -r option which means " Reverses the order of the sort, giving reverse collation or the oldest first, as appropriate."
But which is not the fact.

S1> ls -lrt
-rw-r--r-- 1 3130 10 68 Mar 26 11:45 FILE_WOC.7229343.txt
-rw-r--r-- 1 3130 10 68 Mar 26 11:45 FILE_WOC.7229349.txt
-rw-r--r-- 1 3130 10 68 Mar 26 11:45 FILE_WOC.7229369.txt
-rw-r--r-- 1 3130 10 69 Mar 26 11:45 FILE_WOIR.7229345.txt
-rw-r--r-- 1 3130 10 69 Mar 26 11:45 FILE_WOIR.7229351.txt
-rw-r--r-- 1 3130 10 69 Mar 26 11:45 FILE_WOIR.7229373.txt

Strangely after aplying the option -r, output doesnt differ, it remains same. We tried using many options to get oldest file first and latest as last but invain, the output remains same.


Where as when we check output of same command from Sun OS system, it gives actual output, which is in FIFO manner.

S2>ls -lt
-rw-r--r-- 1 S2 staff 68 Mar 26 11:45 FILE_WOC.7229343.txt
-rw-r--r-- 1 S2 staff 68 Mar 26 11:45 FILE_WOC.7229349.txt
-rw-r--r-- 1 S2 staff 68 Mar 26 11:45 FILE_WOC.7229369.txt
-rw-r--r-- 1 S2 staff 69 Mar 26 11:45 FILE_WOIR.7229345.txt
-rw-r--r-- 1 S2 staff 69 Mar 26 11:45 FILE_WOIR.7229351.txt
-rw-r--r-- 1 S2 staff 69 Mar 26 11:45 FILE_WOIR.7229373.txt

After applying the option -r, it reverses the order i.e. oldest comes first and latest goes down.

S2>ls -lrt
-rw-r--r-- 1 S2 staff 69 Mar 26 11:45 FILE_WOIR.7229373.txt
-rw-r--r-- 1 S2 staff 69 Mar 26 11:45 FILE_WOIR.7229351.txt
-rw-r--r-- 1 S2 staff 69 Mar 26 11:45 FILE_WOIR.7229345.txt
-rw-r--r-- 1 S2 staff 68 Mar 26 11:45 FILE_WOC.7229369.txt
-rw-r--r-- 1 S2 staff 68 Mar 26 11:45 FILE_WOC.7229349.txt
-rw-r--r-- 1 S2 staff 68 Mar 26 11:45 FILE_WOC.7229343.txt

We want the output to behave ideally as on SUN OS, when the order is reversed.

Is there any solution for this?

The ls command is probably using a binary sort to change the order, and the mtime on the file is same (to the nearest second), so that the sort program sees them as equal and does not necessarily retain the original sequence.
The files in your example appear to have file names generated chronologically.
Why not use 'ls' to create a file and then 'sort' the file using '.' as a delimiter and sort on the middle field, or sort on the first field first, and then the second field.