I'm having a problem in understanding the "hash" command in bash: Starting from a clean hash list, I issue a regular command and it is then placed in the hash list (NOTE, option "hashall
/> set -o|grep hash # check relevant setting hashall on # has default, "on" setting /> hash -r # remove hash table /> unalias ls # remove 'ls' alias /> hash # verify hash table empty: hash: hash table empty /> ls /dev/null # use ls command /dev/null /> hash # reprint hash table hits command 1 /usr/bin/ls # note hits=1 ==== I thought that hashing was a way to speed up program access so it wouldn't have to be looked up in the path again. But it doesn't appear to be working from two different perspectives. First, I would expect the 'hit count' to increment, but when I type 'ls' again, it doesn't increment the hit count (continuing from above): /> hash # reprint hash table hits command 1 /usr/bin/ls # hits still 1 /> ls /dev/null # use ls again /dev/null /> hash # reprint hash hits command 1 /usr/bin/ls # Uhoh, count still = 1! ===^==== +-----------------------------------# would have expected a "2" Isn't count supposed to be implemented? The second test case was seeing if the hashed path was used in the absence of a PATH (testing in a subshell): /> bash # start subshell (2)/> unalias ls # get rid of ls alias again (2)/> unset PATH # unset PATH (clears hash table) (2)/> hash # verify empty hash: hash table empty (2)/> hash -p /usr/bin/ls ls # manually add path for ls (2)/> hash -l # list hash correspondences builtin hash -p /usr/bin/ls ls (2)/> ls # Try "ls"... bash: ls: No such file or directory # Uhoh? why no execute? (2)/> hash # reprint table hits command 1 ls # count still 1 (2)/> hash -t ls # print path for 'ls' /usr/bin/ls # appears correct as well ================= So what's the deal? Aren't hits supposed to be incremented? If a hash entry is setup, shouldn't that 1) take precedence over and 2) allow the command to be found, even in the absence of a PATH? This behavior was in my locally built bash: version 3.1.11(2)-release (i686-suse-linux) and the standard Cygwin-distributed bash: version 3.2.3(5)-release (i686-pc-cygwin) If someone could clear this up, that would be great! :-) Linda _______________________________________________ Bug-bash mailing list Bug-bash@gnu.org http://lists.gnu.org/mailman/listinfo/bug-bash
