问题
Is there an R function that would search for s string within a text file? Something like unix grep?
I guess the alternative will be to read the file line by line but was wondering if that can be bypassed by such a function?
回答1:
1) Read it in and use R's grep:
# test input
cat("a 1\n\b 2\nc 3\n", file = "myfile.dat")
grep("a", readLines("myfile.dat"), value = TRUE)
## [1] "a 1"
2) Another possibility if you have grep on your system and on the search path is:
shell("grep a myfile.dat")
## a 1
On Windows you could use findstr in place of grep or if you have Rtools installed but not on your path shell("C:\\Rtools\\bin\\grep a myfile.dat").
来源：https://stackoverflow.com/questions/34708329/searching-for-string-within-a-text-file-in-r