Question: I've many string files (.str), and I want to import them in R (looping on files).
The problem is that the first line is neither columns name nor the beginning of the matrix.. It is a comment line. Idem for the last line.
between those two lines, stand up the matrix I want to import..
How can I do that ?

Thx

Answer: 
You can put your comments anywhere in the data files in the same way that you put your comments an `R` script. For example, if I have a `data.txt` like this:

```
# comment 1
str1
str2
# comment 2
str3
# comment 3
str4
str5# comment 4
str6
str7
# comment 5

```

Then you don't need to do anything to skip the comments:

```
> x<-read.table("data.txt", header=FALSE)
> x
    V1
1 str1
2 str2
3 str3
4 str4
5 str5
6 str6
7 str7
>

```

Note that `comment 4` is not read. You can change the comment character `#` by using the `comment.char` option.
You can skip arbitrary lines anywhere in the file if you combine the `readLines` approach Hong Ooi gives together with negative indexing. Here's an example which skips lines 2-5 in a file that has headers but a number lines of annotation/meta info:

```
lines <- readLines('myfile.txt')
mytable <- read.table(text = lines[-c(2:5)], sep = '\t', header = T)

```