v1.04: shell fixes; update readme

README.md

@@ -12,6 +12,20 @@ licence: Free software GNU GPL 3.0
 
 Source: https://git-repo.iml.unibe.ch/iml-open-source/onfilechange
 
+## Why?
+
+You can use it to trigger actions that are not allowed by another user.
+
+Scenario:
+
+A web developer has access with a non privileged user to maintain an
+application ... and on an update you want to allow him to restart the
+web service without sudo permissions.
+
+Start the onfilechange to watch a defined file as root:
+
+`onfilechange.sh -f /var/www/touch2restart_httpd -c "systemctl restart httpd"`
+
 ## Installation
 
 * Copy the bash script somewhere you like.
@@ -19,24 +33,46 @@ Source: https://git-repo.iml.unibe.ch/iml-open-source/onfilechange
 
 ## Usage
 
-```
-Parameters
-    -c [command]
-        command to execute on a file change
-    -f [filename(s)]
-        filenames to watch; separate multiple files with space and put all in quotes
-    -h
-        show this help
-    -i
-        force inotifywait command
-    -s
-        force stat command
-    -v
-        verbose mode; enable showing debug output
-    -w [integer]
-        for stat mode: wait time in seconds betweeen each test or on missing file; default: 5 sec
+start `./onfilechange.sh -h` to get the help
 
 ```
+______________________________________________________________________________
+
+  T R I G G E R    C O M M A N D    O N    A    F I L E C H A N G E
+______________________________________________________________________________
+                                                                         v1.04
+
+INFO: stat command detected
+HELP:
+        This script checks the change of a given file and triggers
+        a command if it changes
+
+PRAMETERS:
+        -c [command]
+            command to execute on a file change
+        -f [filename(s)]
+            filenames to watch; separate multiple files with space and put all in quotes
+        -h
+            show this help
+        -i
+            force inotifywait command
+        -s
+                force stat command (default mode)
+        -v
+            verbose mode; enable showing debug output
+        -w [integer]
+            for stat mode: wait time in seconds betweeen each test or on missing file; default: 5 sec
+
+EXAMPLES:
+        onfilechange.sh -f /home/me/touchfile.txt -c "ls -l" 
+            watch touchfile.txt and make a file listing on change
+
+        onfilechange.sh -f "/home/me/touchfile.txt home/me/touchfile2.txt" -c "ls -l" 
+            watch touchfile.txt and touchfile2.txt
+
+        onfilechange.sh -f /home/me/touchfile.txt -s -w 10 -c "echo hello" 
+            watch touchfile.txt every 10 sec with stat and show "hello" on a change
+```
 
 ## Test on command line
 
@@ -57,7 +93,7 @@ In `/etc/systemd/system/` create a service config file **onfilechange-demo.servi
 
 ```
 [Unit]
-Description=Onfilechange edemo
+Description=Onfilechange demo
 Wants=multi-user.target
 
 [Service]

onfilechange.sh

@@ -19,6 +19,7 @@
 # ----------------------------------------------------------------------
 # 2019-10-14  v1.0   <axel.hahn@iml.unibe.ch>  first basic version
 # 2019-10-21  v1.03  <axel.hahn@iml.unibe.ch>  use stat as default
+# 2022-03-11  v1.03  <axel.hahn@iml.unibe.ch>  shell fixes
 # ======================================================================
 
 # ----------------------------------------------------------------------
@@ -32,7 +33,7 @@ sWatchFile=
 sMode=
 
 # ---- below are some internal variables 
-sVersion=1.03
+sVersion=1.04
 
 
 # ----------------------------------------------------------------------
@@ -41,6 +42,7 @@ sVersion=1.03
 
 # show help
 function showHelp(){
+	local _self=$( basename $0 )
 cat <<ENDOFHELP
 HELP:
         This script checks the change of a given file and triggers
@@ -63,13 +65,13 @@ PRAMETERS:
             for stat mode: wait time in seconds betweeen each test or on missing file; default: 5 sec
 
 EXAMPLES:
-        `basename $0` -f /home/me/touchfile.txt -c "ls -l" 
+        $_self -f /home/me/touchfile.txt -c "ls -l" 
             watch touchfile.txt and make a file listing on change
 
-        `basename $0` -f "/home/me/touchfile.txt home/me/touchfile2.txt" -c "ls -l" 
+        $_self -f "/home/me/touchfile.txt home/me/touchfile2.txt" -c "ls -l" 
             watch touchfile.txt and touchfile2.txt
 
-        `basename $0` -f /home/me/touchfile.txt -s -w 10 -c "echo hello" 
+        $_self -f /home/me/touchfile.txt -s -w 10 -c "echo hello" 
             watch touchfile.txt every 10 sec with stat and show "hello" on a change
 
 ENDOFHELP
@@ -82,7 +84,7 @@ ENDOFHELP
 # param  string  text message to show
 function wd(){
 	if [ $bDebug -ne 0 ]; then
-		echo "[`date`] DEBUG |" $*
+		echo "[$(date)] DEBUG |" $*
 	fi
 }
 
@@ -110,9 +112,9 @@ function getFilestatus(){
 # global (string) $TmpFile    last/ initial file status
 # global (string) $sTmpFile2  current file status
 function initFilestatus(){
-	getFilestatus >${sTmpFile}
-	wd "`cat ${sTmpFile}`"
-	cp -p ${sTmpFile} ${sTmpFile2}
+	getFilestatus >"${sTmpFile}"
+	wd "$(cat "${sTmpFile}")"
+	cp -p "${sTmpFile}" "${sTmpFile2}"
 }
 
 # for stat: compare file status and execute command on change
@@ -122,7 +124,7 @@ function initFilestatus(){
 # global (string) $sCommand   command to execute
 function compareFilestatus(){
 	getFilestatus >${sTmpFile2}
-	wd "`cat ${sTmpFile2}`"
+	wd "$(cat ${sTmpFile2})"
 	diff ${sTmpFile} ${sTmpFile2}
 	if [ $? -eq 0 ]; then
 		wd "No Change"
@@ -147,7 +149,7 @@ function compareFilestatus(){
 function execCommand(){
 	listFiles
 	echo 
-	echo ">>>>> `date` Executing ${sCommand} ..."
+	echo ">>>>> $(date) Executing ${sCommand} ..."
 	${sCommand}
 }
 
@@ -262,16 +264,16 @@ echo
 # ----------------------------------------------------------------------
 
 echo ">>>>> start"
-myset=`echo ${sWatchFile} | sha1sum | cut -f 1 -d " "`
-sTmpFile="/tmp/`basename $0`-${myset}-last.tmp"
-sTmpFile2="/tmp/`basename $0`-${myset}-current.tmp"
+myset=$(echo "${sWatchFile}" | sha1sum | cut -f 1 -d " ")
+sTmpFile="/tmp/$(basename $0)-${myset}-last.tmp"
+sTmpFile2="/tmp/$(basename $0)-${myset}-current.tmp"
 
 case $sMode in
 	"inotifywait")
 		while true; do
 			listFiles >/dev/null 2>&1 
 			if [ $? -eq 0 ]; then
-				inotifywait -e attrib -e modify ${sWatchFile} && execCommand
+				inotifywait -e attrib -e modify "${sWatchFile}" && execCommand
 			else 
 				echo "ERROR: inotifywait only can notify if all watched files exist."
 				echo "Use parameter -s to use stat for file detection, This mode also allows that a file is deleted."