Ivorde Unix/Linux/Database/Web/Mail Forum

# cat tmp.file
If you use a lot of file redirection in your scripts it's quite easy to overwrite existing files accidentaly.
To prevent this, most shells implement the noclobber environment variable.

# echo "Overwritten content">tmp.file
# cat tmp.file
Overwritten content

# set -o
allexport       off
braceexpand     on
emacs           on
errexit         off
errtrace        off
functrace       off
hashall         on
histexpand      on
history         on
ignoreeof       off
interactive-comments    on
keyword         off
monitor         on
noclobber       off
noexec          off
noglob          off
nolog           off
notify          off
nounset         off
onecmd          off
physical        off
pipefail        off
posix           off
privileged      off
verbose         off
vi              off
xtrace          off

# set -o noclobber; set -o | grep noclobber
noclobber       on

# echo "2nd Overwritten content">tmp.file
bash: tmp.file: cannot overwrite existing file