merge_table_files: Util function to merge multiple table files.
In ngstk: Next-Generation Sequencing (NGS) Data Analysis Toolkit

Util function to merge multiple table files.

merge_table_files(input_files = NULL, files_dir = NULL,
  pattern = ".*.txt", outfn = NULL, add.filename = TRUE,
  read_fun = "read.table", read_params_file = "file",
  read_params = list(sep = "\t", header = TRUE),
  write_fun = "write.table", write_params_x = "x",
  write_params_file = "file", write_params = list(sep = "\t",
  row.names = FALSE), op = list(stringsAsFactors = FALSE))

`input_files`	Basename of files that need to be merged, default is NULL and use the regular expression pattern to select files
`files_dir`	Directory name of input files
`pattern`	Use regular expression to select files in files_dir
`outfn`	Output file path, default is NULL and return the data.frame object
`add.filename`	Wheather to add the merged filename, default is TRUE
`read_fun`	Function to read data, default is read.table
`read_params_file`	Parameter name of input file in read_fun
`read_params`	Other parameters pass to read_fun
`write_fun`	Function to read data, default is read.table
`write_params_x`	Parameter name of output object in read.fun
`write_params_file`	Parameter name of input file in read.fun
`write_params`	Other parameters pass to write_fun
`op,`	Extra option that only take effect in merge process

a <- data.frame(col1=1:6, col2=2:7)
b <- data.frame(col1=6:11, col2=1:6)
file_a <- paste0(tempfile(), '_abcd')
file_b <- paste0(tempfile(), '_abcd')
write.table(a, file_a, sep = '\t', row.names = FALSE)
write.table(b, file_b, sep = '\t', row.names = FALSE)
input_files <- c(file_a, file_b)
x1 <- merge_table_files(input_files = input_files)
x2 <- merge_table_files(files_dir = tempdir(), pattern = '.*_abcd$')
outfn = tempfile()