Peter Pentchev ☫ → To [email protected] @ Thu, Aug 22, 2013 17:10 +0300
> On Thu, Aug 22, 2013 at 07:43:46PM +0600, Sergey Korobitsin wrote: > > Ну, if умеет отрицание: > > if ! echo "$TO_DISK_INFO" | fgrep -e "$SERIAL_SHORT" | fgrep -qe "$SERIALTO"; > then > ... > fi > > В точности то, для чего создана the reserved word "!". Из dash(1): > > If the reserved word ! does not precede the pipeline, the exit status > is the exit status of the last com‐ mand specified in the pipeline. > Otherwise, the exit status is the logical NOT of the exit status of the > last command. That is, if the last command returns zero, the exit > status is 1; if the last command returns greater than zero, the exit > status is zero. > > Или из bash(1): > > The return status of a pipeline is the exit status of the last > command, unless the pipefail option is enabled. If pipefail is > enabled, the pipeline's return status is the value of the last > (rightmost) command to exit with a non-zero status, or zero if all > commands exit successfully. If the reserved word ! precedes a > pipeline, the exit status of that pipeline is the logical negation of > the exit sta‐ tus as described above. The shell waits for all > commands in the pipeline to terminate before returning a value. > > Так что if ! echo ... ; then ... сделает нужное. Да, надо читать маны :-(. Я почему-то решил, что оно будет относиться к первой команде в пайпе. А вообще, лучше perl взять, там unless есть :-). -- Bright regards, Sergey Korobitsin, Chief Research Officer Arta Software, http://arta.kz/ xmpp:[email protected] -- Если мысли сходятся - значит, они ограничены -- Саша & Наташа, периодически -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/[email protected]
