I'm using a Macbook Pro running El Capitan v 10.11.6. I am learning about symlinks, and in the man ln
page, I found the following:
A stat(2) on a symbolic link will return the linked-to file; an lstat(2) must be done to obtain information about the link.
As a test, I created a symlink to a file (in another filesystem, if it matters), as follows:
ln -s /Volumes/foobardir/foobarfile foobarlink
Then I ran lstat foobarlink
to get information on the symlink file itself, but I got the following output:
-bash: lstat: command not found
The command which lstat
returns nothing, which confirms that there is no executable with this name in my filepath.
I am able to execute stat foobarlink
, but I am not sure if the returned stats are for the linked file or the symlink itself. I do see today's date in timestamp form among the output for that command, while running stat foobarfile
shows a date from a few months ago. So I'm guessing this is the output I'm looking for, but I'd like a 2nd opinion.
By the way, running which stat
returns /usr/bin/stat
. A grep
in the /usr/bin
directory for all executables with stat
in their name returns the following:
- db_stat
- diffstat
- httpdstat.d
- jstat
- jstatd
- lockstat
- lpstat
- nfsstat
- plockstat
- snmpnetstat
- snmpstatus
- stat
- uustat
- vm_stat
As I stated above, my guess is that stat
returns the output that I had expected lstat
to return. My questions are:
- why is
lstat
apparently not installed in my system, whenman lstat
recognizeslstat
as a valid command? - Why include manual information for an executable you don't ship with?
brew search lstat
returns no results. Is it possible to installlstat
to my local machine somehow, and are there even any advantages to doing so?
Best Answer
Section 1 of the BSD Manual is for general commands. Section 2 is for system calls, i.e., function calls you might make if programming for your system in the
C
language, or one of its derivatives.The number in parentheses indicates what section of the manual the entry is from. In this case,
lstat(2)
indicates that this page provides information on a system call, not on a standalone binary which can be executed at the command-line.If you typed
man lstat
, you would see the manual page for thelstat
system call.stat
, by contrast, is the name of both a system call and a standalone utility. If you typeman stat
, you will by default get the manual page for the command line utility. To see the system call manual page, you would need to explicitly tellman
which section of the manual to search:https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man5/manpages.5.html is an (outdated) link listing all the sections of the BSD Manual. The sections will be the same on your system, but I can't find that there is a man page explicitly listing the sections.