[R] add text to the first line of an output file

[Henrik Bengtsson]

Alright, if it is the case that the "output file" already exists, then yes
Sven's suggestion is more or less the only solution.

Henrik
On Oct 22, 2014 2:08 AM, "Sven E. Templer" <sven.templer at gmail.com> wrote:

> He wants to prepend, not append.
>
> On 22 October 2014 11:04, Henrik Bengtsson <hb at biostat.ucsf.edu> wrote:
> > You can! Open a file connection and write to that. Whatever write
> commands
> > you use will append to the output. Don't forget to close the connection
> at
> > the end. See ?file
> >
> > Henrik
> >
> > On Oct 22, 2014 12:33 AM, "Sven E. Templer" <sven.templer at gmail.com>
> wrote:
> >>
> >> Hi.
> >>
> >> You can't.
> >>
> >> But using a second file where you first write your header and then
> >> append the original file is a solution. ?cat and ?write.table with a
> >> focus on the 'append' argument should help. you can then use ?unlink
> >> to delete the original file and ?file.rename to rename the second, if
> >> desired.
> >>
> >> Best, Sven.
> >>
> >> On 22 October 2014 02:32, YIHSU CHEN <yihsuc at gmail.com> wrote:
> >> > Hi guys;
> >> >
> >> > I want to write some text at the first line of an output file.  The
> >> > output
> >> > file will be used for other software.  In particular, the following
> text
> >> > "ampl.tab 2 1" needs to be added to the first line of an  df output
> >> > file.
> >> > As a hypothetic example, the output in text file should be like:
> >> >
> >> > ampl.tab 2 1
> >> > A  B
> >> > 2   3
> >> > 4   6
> >> > 2   0
> >> >
> >> > Thanks for help.
> >> >
> >> > Yihsu
> >> >
> >> >         [[alternative HTML version deleted]]
> >> >
> >> > ______________________________________________
> >> > R-help at r-project.org mailing list
> >> > https://stat.ethz.ch/mailman/listinfo/r-help
> >> > PLEASE do read the posting guide
> >> > http://www.R-project.org/posting-guide.html
> >> > and provide commented, minimal, self-contained, reproducible code.
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> >> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
>

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