diff options
| -rw-r--r-- | usr.bin/mktemp/mktemp.1 | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/usr.bin/mktemp/mktemp.1 b/usr.bin/mktemp/mktemp.1 index 4e48352f2e5..f8622c6a3a9 100644 --- a/usr.bin/mktemp/mktemp.1 +++ b/usr.bin/mktemp/mktemp.1 @@ -1,4 +1,4 @@ -.\" $OpenBSD: mktemp.1,v 1.7 1998/03/07 22:18:16 millert Exp $ +.\" $OpenBSD: mktemp.1,v 1.8 1998/03/19 06:13:37 millert Exp $ .\" .\" Copyright (c) 1989, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -76,6 +76,19 @@ is created with mode 0600 (unless the .Fl u flag is given) and the filename is printed to standard output. +.Pp +.Nm Mktemp +is provided to allow shell scripts to safely use temporary files. +Traditionally, many shell scripts take the name of the program with +the pid as a suffix and use that as a temporary file name. This +kind of naming scheme is predictable and the race condition it creates +is easy for an attacker to win. A safer, though still inferior, approach +is to make a temporary directory using the same naming scheme. While +this does allow one to guarantee that a temporary file will not be +subverted, it still allows a simple denial of service attack. For these +reasons it is suggested that +.Nm +be used instead. .Sh OPTIONS .Bl -tag -width indent The available options are as follows: @@ -125,8 +138,9 @@ zero length instead of checking $?. This would allow the check to be done later one in the script (since $? would get clobbered by the next shell command). .Sh SEE ALSO -.Xr mkstemp 3 , -.Xr mktemp 3 +.Xr mktemp 3 , +.Xr mkdtemp 3 , +.Xr mkstemp 3 .Sh HISTORY The .Nm |