R help - Dec 2015 - help using SED

All,

I have not used SED in the past so I am continuing to read its documentation but
I need some help with R

Here is my SED command which works:
? system("sed -i '' ?'/^[\r#]/d; /AGENCY/d'
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/Temp_CashFlow/blx_test.cfm")

Here are my R commands which do not work. ?
ReadCF <- paste("system(sed -i '' '/^[\r#]/d; /AGENCY/d'
",?
system.file(package = "BondLab"),"/Temp_CashFlow/",?
CashFlowData, ".cfm)", sep ="")

eval(parse(text = ReadCF))
I have managed to determine that the problem is the missing quotes but I do not
know how to get those included in the below R command.

Any help is appreciated

Glenn

> On Dec 5, 2015, at 4:49 PM, Glenn Schultz <glennmschultz at me.com>
wrote:
> 
> All,
> 
> I have not used SED in the past so I am continuing to read its
documentation but I need some help with R
> 
> Here is my SED command which works:
>   system("sed -i ''  '/^[\r#]/d; /AGENCY/d'
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/Temp_CashFlow/blx_test.cfm")
> 
> Here are my R commands which do not work.  
> ReadCF <- paste("system(sed -i '' '/^[\r#]/d;
/AGENCY/d' ",
> system.file(package = "BondLab"),"/Temp_CashFlow/", 
> CashFlowData, ".cfm)", sep ="")
> 
> eval(parse(text = ReadCF))
> I have managed to determine that the problem is the missing quotes but I do
not know how to get those included in the below R command.
I see no explanation of what you are attempting, but the method of including an
actual quote in an R character vector element is to escape it:
> cat("\"")
"
> nchar("\"")
[1] 1


? 


David Winsemius
Alameda, CA, USA

> On 06 Dec 2015, at 04:53 , David Winsemius <dwinsemius at
comcast.net> wrote:
> 
>> 
>> On Dec 5, 2015, at 4:49 PM, Glenn Schultz <glennmschultz at
me.com> wrote:
>> 
>> All,
>> 
>> I have not used SED in the past so I am continuing to read its
documentation but I need some help with R
>> 
>> Here is my SED command which works:
>>  system("sed -i ''  '/^[\r#]/d; /AGENCY/d'
/Library/Frameworks/R.framework/Versions/3.2/Resources/library/BondLab/Temp_CashFlow/blx_test.cfm")
>> 
>> Here are my R commands which do not work.  
>> ReadCF <- paste("system(sed -i '' '/^[\r#]/d;
/AGENCY/d' ",
>> system.file(package = "BondLab"),"/Temp_CashFlow/",
>> CashFlowData, ".cfm)", sep ="")
>> 
>> eval(parse(text = ReadCF))
>> I have managed to determine that the problem is the missing quotes but
I do not know how to get those included in the below R command.
> 
> I see no explanation of what you are attempting, but the method of
including an actual quote in an R character vector element is to escape it:
> 
>> cat("\"")
> "
>> nchar("\"")
> [1] 1
> 
At any rate, eval(parse(... is just silly (fortune(181); fortune(106)). 

Just use paste()  or --- probably better ---sprintf() to construct the command,
and then do

cmd <- ....
system(cmd)

A further advantage is that you can cat(cmd, \n)  before running it and see
whether it contains what you intended.

I think (but you check) that this works:

fmt <- "sed -i ''  '/^[\r#]/d; /AGENCY/d'
%s/Temp_CashFlow/%s.cfm"
cmd <- sprintf(fmt, system.file(package = "BondLab"), CashFlowData)
system(cmd)

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com