Dear Yichao,
Ah. That makes sense now. Thank you.
-Mike
On Wednesday, February 3, 2016 at 3:33:11 PM UTC-8, Yichao Yu wrote:
>
> On Wed, Feb 3, 2016 at 6:01 PM, Michael Wojnowicz <mwoj...@uci.edu
> <javascript:>> wrote:
> > Hi Julia Users,
> >
> >
> > I'm running Julia 0.3.8, commit 507821*. I want to search through a csv
> to
> > find line numbers of rows which match an expression, in this case "=",
> and
> > then save the resulting row indices to a file.
> >
> >
> > In terminal, I can do this:
> >
> > grep -n -v "=" 20150817global.json.mv.fvm.exported.csv | awk -F: '{print
> > $1}' > ctsfeats.csv
> >
> > In Julia version 0.3.8, the pipeline function did not yet exist. There
> is,
> > though, a |> command for piping. However, the command
> >
> > cmd=`grep -n -v "=" 20150817global.json.mv.fvm.exported.csv` |> `awk -F:
> > '{print $1}' > ctsfeats.csv`
> >
> > run(cmd)
> >
> > fails with messsage
> >
> > awk: cmd. line:1: fatal: cannot open file `>' for reading (No such file
> or
> > directory)
> >
> > ERROR: failed process: Process(`awk -F: '{print $1}' > ctsfeats.csv`,
> > ProcessExited(2)) [2]
> >
> > in pipeline_error at process.jl:515
> >
> > in run at process.jl:479
> >
> >
> > I had originally posted this question in the wrong place (in the
> "issues"
> > forum), where Matt Bauman was kind enough to offer the advice to also
> pipe
> > to the file, a la
> >
> > `grep …` |> `awk …` |> "ctsfeats.csv"
>
> `<cmd>` returns a command object so don't change the normal double
> quote for filename to backtick if you want to redirect it to a file
> instead of a command of that name.
>
> >
> >
> > However, this command also fails
> >
> > cmd=`grep -n -v "=" 20150817global.json.mv.fvm.exported.csv` |> `awk -F:
> > '{print $1}'` |> `ctsfeats.csv`
> >
> > with error message
> >
> > julia> run(cmd)
> >
> > ERROR: could not spawn `ctsfeats.csv`: no such file or directory
> (ENOENT)
> >
> > in _jl_spawn at process.jl:217
> >
> > in spawn at process.jl:348
> >
> > in spawn at process.jl:260
> >
> > in spawn at process.jl:389
> >
> > in run at process.jl:478
> >
> >
> > Does anybody have any ideas? Please excuse my relative naivete; my
> training
> > in in mathematics and statistics, not computer science.
> > Thanks for your time.
> >
> > -Mike
> >
> >
>
