On Oct 21 18:09, cygwin wrote: > When I type 'ps', I get as expected the following processes: > > PID PPID PGID WINPID TTY UID STIME COMMAND > 18036 3188 18036 17792 pty0 1001 16:54:33 /usr/bin/ps > 3188 1688 3188 3212 pty0 1001 06:59:16 /usr/bin/bash > 1688 1 1688 1688 ? 1001 06:59:15 /usr/bin/mintty > 2392 1 2392 2392 ? 1001 11:00:03 /usr/bin/ssh-agent > > When I type 'ps | grep bash', about 2/3 of the time, I get: > 3188 1688 3188 3212 pty0 1001 06:59:16 /usr/bin/bash > > HOWEVER, about 1/3 of the time, I get: > 16832 3188 17792 16832 pty0 1001 16:56:44 /usr/bin/bash > 3188 1688 3188 3212 pty0 1001 06:59:16 /usr/bin/bash
When you pipe ps to grep, the shell forks and execs two processes, ps and grep. What you see is one of the forked bash processes. They are shortlived, but depending on the order of execution they may still linger in the process list when ps creates the process list. > And there is no bash process launched in the interim. Moreover, this > second PID jumps around (both up and down) wildly rather than being > constant or even relatively sequential. PIDs under Windows are not sequential. > In such cases, ps -W, similarly generates 2 bash processes: > > 3188 1688 3188 3212 pty0 1001 06:59:16 /usr/bin/bash > 16460 0 0 16460 pty0 1001 17:44:29 > C:\cygwin\bin\bash.exe > > Even more interesting, when I type 'ps | grep ssh-agent', about 2/3 of the > time, I get: > 2392 1 2392 2392 ? 1001 11:00:03 /usr/bin/ssh-agent > > HOWEVER, about 1/3 of the time, I get: > 2392 1 2392 2392 ? 1001 11:00:03 /usr/bin/ssh-agent > 19176 0 0 19176 pty0 1001 Dec 31 /usr/bin/ssh-agent Hmm, I can't reproduce this one. I tried a hundreds of times, but there was not a single instance of bash shown as a Windows process. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
pgppNvTHmJFPw.pgp
Description: PGP signature
