Bug 28146
| Summary: | RETVAL=$? isn't always reliable due to daemon()/fork() | ||
|---|---|---|---|
| Product: | [Retired] Red Hat Linux | Reporter: | Pekka Savola <pekkas> |
| Component: | openssh | Assignee: | Tomas Mraz <tmraz> |
| Status: | CLOSED NOTABUG | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 7.0 | CC: | dr |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i386 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2005-02-02 15:49:14 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
This is not a bug but rather a feature of the current SYS V init scripts style code. The RETVAL can reflect only errors before the daemonization happens. There is nothing we can do with that. |
This is probably a more generic problem due to a coding style, but it happened to me with OpenSSH, so I'll put it in the record here. (just trying to start sshd when it's already running) # ./sshd -d [snip] socket: Invalid argument debug1: Bind to port 22 on 0.0.0.0. fatal: Cannot bind any address. # echo $? 255 # ./sshd # echo $? 0 With './sshd', the same fatal message is printed to syslog. --- Now, the init script e.g. does: --- action $"Starting $prog: " /usr/sbin/sshd RETVAL=$? --- now RETVAL is 0 (as above), even though sshd really fatal()'ed out with 255 exit code. Kevin Steves <stevesk.com> explained on openssh-univ-dev list: --- this one has forked and detached from the terminal at the point of that error. its parent does exit(0) in daemon() which is what the shell sees. --- So, it'd appear RETVAL or exit codes are not always too reliable. Luckily in this case it doesn't really matter that RETVAL is mistaken to be 0.