diff --git a/peaks-report.Rmd b/peaks-report.Rmd
index 48d661a..2abf76e 100644
--- a/peaks-report.Rmd
+++ b/peaks-report.Rmd
@@ -20,6 +20,7 @@ knitr::opts_chunk$set(echo = FALSE, warning = FALSE)
 library("ggplot2")
 library("DT")
 library("scales")
+source("peaktools.R")
 
 # ~~~~~ FUNCTIONS ~~~~~ # 
 find_all_beds <- function (input_dirs, name_pattern = FALSE) {
diff --git a/peaktools.R b/peaktools.R
new file mode 100644
index 0000000..a0f7e9c
--- /dev/null
+++ b/peaktools.R
@@ -0,0 +1,98 @@
+#!/usr/bin/env Rscript
+
+# ~~~~~ PACKAGES ~~~~~ # 
+library("tools")
+
+
+# ~~~~~ FUNCTIONS ~~~~~ # 
+msprintf <- function(fmt, ...) {
+    message(sprintf(fmt, ...))
+}
+
+mycat <- function(text){
+    # print formatted text in Rmd
+    cat(gsub(pattern = "\n", replacement = "  \n", x = text))
+}
+
+remove_ext <- function(input_file){
+    # remove extension from filename
+    old_ext <- file_ext(input_file)
+    filename_base <- gsub(pattern = sprintf('.%s$', old_ext), replacement = '', x = basename(input_file))
+    return(filename_base)
+}
+
+sort_bed_df <- function(df){
+    # sort a bed df and remove duplicate entries
+    df <- df[1:3]
+    df <- df[ order(df[,1], df[,2]), ]
+    df <- df[! duplicated(df), ]
+    return(df)
+}
+
+make_filename <- function (input_file, new_ext, out_dir = FALSE) {
+    # Convert '/path/to/file.bed' to '/path/to/file_annotations.tsv'
+    old_ext <- file_ext(input_file)
+    filename_base <- gsub(pattern = sprintf('.%s$', old_ext), replacement = '', x = basename(input_file))
+    filename_new <- sprintf('%s.%s', filename_base, new_ext)
+    new_path <- file.path(dirname(input_file), filename_new)
+    if(out_dir != FALSE){
+        new_path <- file.path(out_dir, new_path)
+        dir.create(path = dirname(new_path), recursive = TRUE, showWarnings = FALSE)
+    }
+    return(new_path)
+}
+
+check_numlines <- function(input_file, min_value = 0) {
+    # make sure a file has >0 lines
+    has_enough_lines <- FALSE
+    if (length(readLines(input_file)) > min_value) has_enough_lines <- TRUE
+    return(has_enough_lines)
+}
+
+
+validate_file <- function(input_file) {
+    # make sure that all files are .bed, and that they have >0 lines
+    # validation passes if all files are .bed
+    all_exist <- all(file.exists(input_file))
+    if ( ! isTRUE(all_exist)) {
+        msprintf("WARNING: Input file do not exist:\n%s\nFile will not be processed\n\n", input_file)
+        return(FALSE)
+    }
+    all_bed <- all(grepl(pattern = '*.bed$', x = basename(input_file)))
+    if ( ! isTRUE(all_bed)) {
+        msprintf("WARNING: Input file is not .bed:\n%s\nFile will not be processed\n\n", input_file)
+        return(FALSE)
+    }
+    all_min_linenum <- all(sapply(input_file, check_numlines))
+    if ( ! isTRUE(all_min_linenum)) {
+        msprintf("WARNING: Input file does not have enough lines:\n%s\nFile will not be processed\n\n", input_file)
+        return(FALSE)
+    }
+    return(TRUE)
+}
+
+
+
+find_all_beds <- function (input_dirs) {
+    # find all .bed files in the supplied dirs
+    return(dir(input_dirs, pattern = '.bed', full.names = TRUE, recursive = TRUE))
+}
+
+
+get_sampleID <- function(input_file, id_dirname = FALSE){
+    # get the sample ID for a file
+    # right now just use the basename but maybe some day do something fancier here
+    sampleID <- basename(input_file)
+    if(isTRUE(id_dirname)) sampleID <- basename(dirname(input_file))
+    return(sampleID)
+}
+
+get_sample_outdir <- function(parent_outdir, sampleID, create = TRUE){
+    # make a path for the sample's output directory
+    output_path <- file.path(parent_outdir, sampleID)
+    if(isTRUE(create)) dir.create(output_path, recursive = TRUE)
+    return(output_path)
+}
+
+
+