R help - Jan 2021 - rbind common header to file list

Dear all,

I have more than 200 text files in a folder without header - example below.
I would like to read, add a common date header to all the files, and write
(replace) the files.

## Read files
filelist = list.files(pattern = ".*.txt")
datalist = lapply(filelist, function(x)read.table(x, header=F))

## What I want to add
date <- 20000101
datalist _new <- lapply(datalist, function(x) rbind(x, date))

How do I add this date as a common header and replace the files? Any help
will be highly appreciated. Thank you.

Best,

Milu

## Sample data
xy <- dput(head(x,6))
structure(list(V1 = c("-5.28082885742185,-0.509039307",
"-6.09873046874998,-0.349584961",
"-2.07150878906248,6.264276123",
"-1.11102905273435,6.365716553",
"2.37749633789065,14.57106934",
"4.9619079589844,18.91350708"
)), row.names = c(NA, 6L), class = "data.frame")

	[[alternative HTML version deleted]]

a) I recommend _not_ overwriting the input files. Very difficult to
debug/recover if anything goes wrong.

b) I recommend making a function that takes the file name, source directory, and
destination directory, and reads the file, makes the change, and writes it to
the output directory.

c) Your life may be easier if you use readLines() and writeLines rather than a
more sophisticated parsing function like read.table(). Adding a new string to a
vector of strings is straightforward.

On January 19, 2021 3:45:53 PM PST, Miluji Sb <milujisb at gmail.com>
wrote:
>Dear all,
>
>I have more than 200 text files in a folder without header - example
>below.
>I would like to read, add a common date header to all the files, and
>write
>(replace) the files.
>
>## Read files
>filelist = list.files(pattern = ".*.txt")
>datalist = lapply(filelist, function(x)read.table(x, header=F))
>
>## What I want to add
>date <- 20000101
>datalist _new <- lapply(datalist, function(x) rbind(x, date))
>
>How do I add this date as a common header and replace the files? Any
>help
>will be highly appreciated. Thank you.
>
>Best,
>
>Milu
>
>## Sample data
>xy <- dput(head(x,6))
>structure(list(V1 = c("-5.28082885742185,-0.509039307",
>"-6.09873046874998,-0.349584961",
>"-2.07150878906248,6.264276123",
"-1.11102905273435,6.365716553",
>"2.37749633789065,14.57106934",
"4.9619079589844,18.91350708"
>)), row.names = c(NA, 6L), class = "data.frame")
>
>	[[alternative HTML version deleted]]
>
>______________________________________________
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-- 
Sent from my phone. Please excuse my brevity.