From c95cc96a313a17c08b4292271da6cd901f8e0610 Mon Sep 17 00:00:00 2001
From: omer-musa-battal <34798379+omer-musa-battal@users.noreply.github.com>
Date: Thu, 14 Nov 2019 15:24:06 +0300
Subject: [PATCH] macOS compatibility for filesystem type checks

updates #170, by introducing cases for different OSes. Also includes fixes for #172 and part of #181.
---
 rsync_tmbackup.sh | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/rsync_tmbackup.sh b/rsync_tmbackup.sh
index 1bc24ee..2efc89b 100755
--- a/rsync_tmbackup.sh
+++ b/rsync_tmbackup.sh
@@ -250,12 +250,24 @@ fn_test_file_exists_src() {
 	fn_run_cmd_src "test -e '$1'"
 }
 
+# Outputs 0 if given directory is not a type of FAT filesystem.
+# Outputs greater than 0 otherwise. Has to be implemented for different OSes.
 fn_df_t_src() {
-	fn_run_cmd_src "df -T '${1}'"
+	OSTYPE_STR="$(fn_run_cmd_src 'echo ${OSTYPE}')"
+	case "${OSTYPE_STR}" in
+		linux*) fn_run_cmd_src "df -T '${1}' | awk 'NR==2' | awk '{print \$2}' | grep -c -i -e 'fat'" ;;
+		darwin*) fn_run_cmd_src "df -T msdos,exfat ${1} | awk 'NR==2' | grep -c -e '${1%/}'" ;;
+		*) echo 0 ;; # not implemented OSes, do not perform check.
+	esac
 }
 
 fn_df_t() {
-	fn_run_cmd "df -T '${1}'"
+	OSTYPE_STR="$(fn_run_cmd 'echo ${OSTYPE}')"
+	case "${OSTYPE_STR}" in
+		linux*) fn_run_cmd "df -T '${1}' | awk 'NR==2' | awk '{print \$2}' | grep -c -i -e 'fat'" ;;
+		darwin*) fn_run_cmd "df -T msdos,exfat ${1} | awk 'NR==2' | grep -c -e '${1%/}'" ;;
+		*) echo 0 ;; # not implemented OSes, do not perform check.
+	esac
 }
 
 # -----------------------------------------------------------------------------
@@ -369,7 +381,7 @@ if [ -n "$SSH_SRC_FOLDER" ]; then
 fi
 
 # Exit if source folder does not exist.
-if ! fn_test_file_exists_src ${SRC_FOLDER}; then
+if ! fn_test_file_exists_src "${SRC_FOLDER}"; then
 	fn_log_error "Source folder \"${SRC_FOLDER}\" does not exist - aborting."
 	exit 1
 fi
@@ -406,13 +418,12 @@ fi
 # If one of them is FAT, use the --modify-window rsync parameter
 # (see man rsync) with a value of 1 or 2.
 #
-# The check is performed by taking the second row
-# of the output of the first command.
-if [[ "$(fn_df_t_src "${SRC_FOLDER}" | awk '{print $2}' | grep -c -i -e "fat")" -gt 0 ]]; then
+# fn_df_t commands output 0 when disk is not FAT, and >0 otherwise.
+if [[ "$(fn_df_t_src "${SRC_FOLDER}/")" -gt 0 ]]; then
 	fn_log_info "Source file-system is a version of FAT."
 	fn_log_info "Using the --modify-window rsync parameter with value 2."
 	RSYNC_FLAGS="${RSYNC_FLAGS} --modify-window=2"
-elif [[ "$(fn_df_t "${DEST_FOLDER}" | awk '{print $2}' | grep -c -i -e "fat")" -gt 0 ]]; then
+elif [[ "$(fn_df_t "${DEST_FOLDER}/")" -gt 0 ]]; then
 	fn_log_info "Destination file-system is a version of FAT."
 	fn_log_info "Using the --modify-window rsync parameter with value 2."
 	RSYNC_FLAGS="${RSYNC_FLAGS} --modify-window=2"