3

Given

  • a directory
  • a sh pattern which yields a subset of files directly in this directory (like *.log)
  • a sh pattern which can, given a filename,

what is the fastest way (in ksh) to obtain for each file filtered in by the pattern:

  • its name
  • the date and time of its last modification (i.e. text appended)
  • the date and time where it was created (supposing it was created in the directory were it is when we access it)

Ideally, it would work on both:

  • AIX 6100-04-03-1009
  • Linux 2.6.18
  • SunOS 5.10
fixer1234
  • 28,064
Pierre Gardin
  • 1,602

3 Answers3

2

A Posix file system node typically has three time attributes:

  • atime (access time) -- when was the file last read
  • mtime (modification time) -- when was it last written to.
  • ctime (change time) -- when was its inode (metadata) changed.

The ctime attribute is frequently misunderstood as creation time, and sometimes it is, which tends to confuse people.

POSIX shells have no standard way of extracting these three attributes, and you will depend on the ls command. ls -l $file by default shows modification time.

  • ls -lc $file shows ctime
  • ls -lu $file shows atime

It is recommended to use ls --time-style=full-iso or another iso format for consistent output, if you are on a GNU/linux system.

In Perl and other scripting languages, it's easier to stat() a file and access its attributes. Perl even has the -M, -A, and -C operators that return mtime, atime, and ctime for a file system object. Note the time offset, though. Perl tends to report times relative to the process start time.

Henk Langeveld
  • 393
0

This might be a GNU extension, but GNU find has printf formats for all 3 times, excluding the "birth" time. (That requires a Linux statx system call; current versions of coreutils stat can get all 4 times).

find -printf '%a \t%c \t%t  \t%f\n'

will print all 3 times like

Tue Dec  8 07:49:12.3585942200 2020     Tue Dec  8 07:49:27.9582201460 2020     Tue Dec  8 07:49:27.9582201460 2020     ./foo.c

You can use %Ak where k is a format specifier, same for ctime and mtime, to print in a different format. See the Linux man page

https://www.unix.com/man-page/posix/1p/find/ doesn't mention -printf at all, so you might need perl or other non-POSIX tools.

Peter Cordes
  • 6,345
0

Apologies for not writing the awk/sed for you, but the stat command will provide accessed, modified, and changed times. It will glob for you. Im not sure if it works in AIX, I have no access to that presently.

Sirch
  • 121