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help with grep list files

4 messages · Glenn Schultz, Rui Barradas, Rolf Turner +1 more

Glenn Schultz
# 
All,

I have the following files in a directory and I would like only a list of those starting with ?lld" and ending with ?dat?.  I used the following and it gives me the lld files 

 list.files(path = readpath, pattern = "^lld[A-Z0-9]")
 
to get just .dat files I tried

 list.files(path = readpath, pattern = "^lld[A-Z0-9].dat$?) but nothing is returned


below is a dput from the first command.  $ is an end of line anchor correct?  What am I doing wrong?


Best,
Glenn

c("lld022017_AB7755_AS0038.dat", "lld022017_AS0039_AS5210.dat", 
"lld022017_AS5211_AS7917.dat", "lld022017_AS7918_AT8661.dat", 
"lld022017_AT8662_AW6667.dat", "lld022017_AW6668_AZ3066.dat", 
"lld022017_AZ3067_BC9534.dat", "lld022017_BC9535_MA2230.dat", 
"lld022017_MA2231_MB0288.dat", "lld022017.zip")
Rui Barradas
# 
Hello,

Maybe if you change the pattern to

"^lld[A-Z0-9]*\\.dat$"

Hope this helps,

Rui Barradas

Em 20-02-2017 21:41, Glenn Schultz escreveu:
Rolf Turner
#
On 21/02/17 10:41, Glenn Schultz wrote:
list.files(pattern="^lld.*\\.dat$")

seems to work for me.

cheers,

Rolf
David Wolfskill
#
On Mon, Feb 20, 2017 at 03:41:50PM -0600, Glenn Schultz wrote:
Note that help(list.files) mentions (among other things):

| Note:
| 
|      File naming conventions are platform dependent.  The pattern
|      matching works with the case of file names as returned by the OS.

Also, your pattern ("^lld[A-Z0-9].dat$") does not include the '_'
character.

I was able to get the results you requested in my environment (FreeBSD
stable/11) using:

list.files(path = readpath, pattern = "^lld[_A-Z0-9]*.dat$")

(Note the '*' in there, as well.)

But "filename globbing" is not the same as "regular expressions," and as
the above-cited Note warns, results may well be platform-dependent, so
be careful.
Peace,
david