Date: Fri, 3 Nov 2017 14:50:26 +0100 From: Polytropon <freebsd@edvax.de> To: Ian Smith <smithi@nimnet.asn.au> Cc: byrnejb@harte-lyne.ca, freebsd-questions@freebsd.org Subject: Re: Reconstruct a bash_history file Message-ID: <20171103145026.16c4aa5a.freebsd@edvax.de> In-Reply-To: <20171103232233.P7397@sola.nimnet.asn.au> References: <mailman.75.1509710402.96436.freebsd-questions@freebsd.org> <20171103232233.P7397@sola.nimnet.asn.au>
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On Fri, 3 Nov 2017 23:37:29 +1100 (EST), Ian Smith wrote:
> In freebsd-questions Digest, Vol 700, Issue 5, Message: 7
> On Thu, 2 Nov 2017 21:46:34 +0100 Polytropon <freebsd@edvax.de> wrote:
>
> > You need the YYYY-MM-DD HH:MM:SS timestamp to the Epoch format,
> > prefix it with a #, and put the command on a new line.
> >
> > Maybe like this, if you don't mind a multiple-line one-liner
> > of regular shell script:
> >
> > $ cat history.txt | while read LINE; do DATETIME=`echo $LINE | cut -d ':' -f 1-3`; TIMESTAMP=`date -j -f "%Y-%m-%d %H:%M:%S" "${DATETIME}" "+#%s"`; COMMAND=`echo $LINE | cut -d ':' -f 4-`; echo "${TIMESTAMP}"; echo "${COMMAND}" | sed "s/^ //"; done > bash_history.txt
> >
> > This version is easier to read:
> >
> > cat history.txt | while read LINE; do
> > DATETIME=`echo $LINE | cut -d ':' -f 1-3`
> > TIMESTAMP=`date -j -f "%Y-%m-%d %H:%M:%S" "${DATETIME}" "+#%s"`
> > COMMAND=`echo $LINE | cut -d ':' -f 4-`
> > echo "${TIMESTAMP}"
> > echo "${COMMAND}" | sed "s/^ //"
> > done > bash_history.txt
> >
> > It features the "useless use of cat" line the one-liner. ;-)
>
> Nice work!
>
> A most useful "useless use of cat", but even that could be avoided with:
>
> while read LINE; do
> [..]
> done < history.txt > bash_history.txt
Fully right. I thought about it after hitting "Send".
Additionally, the qupting for the echo commands isn't
that efficient, and I'd suggest do move the sed step
to the COMMAND= line. :-)
--
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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