diff options
| author |   millert <millert@openbsd.org> | 2001-12-07 20:21:17 +0000 |
|---|---|---|
| committer | millert <millert@openbsd.org> | 2001-12-07 20:21:17 +0000 |
| commit | 9ad5f3214e457ca36883fe5e7415a2f5e292d3dd (patch) | |
| tree | 90dfc79c43e2b5904304046fe4b46364388467cb /lib/libc | |
| parent | Add CAVEATS section pointing out the dangers of closing fds <= 2 (diff) | |
| download | wireguard-openbsd-9ad5f3214e457ca36883fe5e7415a2f5e292d3dd.tar.xz wireguard-openbsd-9ad5f3214e457ca36883fe5e7415a2f5e292d3dd.zip | |
Document signal handling in readpassphrase(3)
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/gen/readpassphrase.3 | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/lib/libc/gen/readpassphrase.3 b/lib/libc/gen/readpassphrase.3 index b39ce37bd3f..0abfbf3de7e 100644 --- a/lib/libc/gen/readpassphrase.3 +++ b/lib/libc/gen/readpassphrase.3 @@ -1,4 +1,4 @@ -.\" $OpenBSD: readpassphrase.3,v 1.3 2001/08/06 10:42:25 mpech Exp $ +.\" $OpenBSD: readpassphrase.3,v 1.4 2001/12/07 20:21:17 millert Exp $ .\" .\" Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com> .\" All rights reserved. @@ -104,12 +104,57 @@ if (compare(transform(passbuf), epass) != 0) memset(passbuf, 0, sizeof(passbuf)); .Ed +.Sh SIGNALS +.Fn readpassphrase +will catch the following signals: +.Pp +.Bd -literal -offset indent -compact +SIGINT +SIGHUP +SIGQUIT +SIGTERM +SIGTSTP +.Ed +.Pp +When one of the above signals is intercepted, terminal echo will +be restored if it had previously been turned off. +If a signal handler was installed for the signal when +.Fn readpassphrase +was called that handler is then executed. +If no handler was previously installed for the signal then the +default action is taken as per +.Xr sigaction 2 . +.Pp +The +.Dv SIGTSTP +signal (stop signal generated from keyboard) is treated specially. +When the process is resumed after it has been stopped, +.Fn readpassphrase +will reprint the prompt and the user may then enter a passphrase. +.Pp +Note: if the handler for a signal was +.Dv SIG_IGN +(ignore signal) when +.Fn readpassphrase +was called, terminal echo will not be restored to its previous value +(since there is no other handler to call). +This is only a problem when the program that calls +.Fn readpassphrase +is running as a child process of another program that also +receives the signal (and exits or suspends due to it). +Because of this it is suggested that these signals be blocked +instead of ignored. +See +.Xr sigprocmask 3 +for details on blocking signal receipt. .Sh FILES .Bl -tag -width /dev/tty -compact .It Pa /dev/tty .El .Sh SEE ALSO -.Xr getpass 3 +.Xr sigaction 2 , +.Xr getpass 3 , +.Xr sigprocmask 3 .Sh HISTORY The .Fn readpassphrase |