sequencer - addConf support for backslash escapes

sequencer - new api function rmold to remove oldest files in a directory

sequencer.sh

@@ -151,13 +151,13 @@ helpApi(){
 sequencer.sh API
 
 The sequencer.sh build-in functions are available in all sequence functions:
-- seq_config
+- seq_config()
   If optional seq_config is defined in the sequence, it will be called once before execution of steps.
-- step_[1-${_sqr_stepMax}]_info
-- step_[1-${_sqr_stepMax}]_alias
+- step_[1-${_sqr_stepMax}]_info()
+- step_[1-${_sqr_stepMax}]_alias()
 - step_[1-${_sqr_stepMax}]_noconf=
   No need to call seq_config for this step.
-- step_[1-${_sqr_stepMax}]
+- step_[1-${_sqr_stepMax}]()
 
 sequencer.sh global variables:
 
@@ -189,6 +189,7 @@ USAGE_API
         -a : append to existing file
         -s : skip if CONFIGFILE exists (no backup and entry in missing conf)
         -m : only add content to missing conf and warn user
+        -e : enable interpretation of backslash escapes (ignored for -f)
         -f : <SOURCE> is a file
       <SOURCE>
         Text or file (-f) to create or added to <DESTINATION FILE>
@@ -342,6 +343,14 @@ USAGE_API
   cat <<USAGE_API
     Returns true if seq runs non-interactive (-q|-qq).
 
+USAGE_API
+  echo -e "$(col green) rmold [OPTION] <DIRECTORY>$(col off)"
+  cat <<USAGE_API
+    Remove oldest non hidden files in DIRECTORY and retain given NUMBER (default 5).
+      [OPTION]
+        -h          : Remove also hidden files
+        -r <NUMBER> : Retain NUMBER files in Directory
+
 USAGE_API
   echo -e "$(col green) root$(col off)"
   cat <<USAGE_API
@@ -591,6 +600,9 @@ contextExe() { (( _sqr_contextExe )); }
 # Starts the detected system text editor
 editor() { exe "${_sqr_editor}" "$@"; }
 
+# Escaping non-printable characters with the proposed POSIX $'' syntax
+escpath() { printf "%q" "$*"; }
+
 ### interactive
 # confirm [OPTIONS] [--] [QUESTION]
 #  Default (empty character) = no
@@ -679,8 +691,54 @@ ask() {
   fi
 }
 
-# Escaping non-printable characters with the proposed POSIX $'' syntax
-escpath() { printf "%q" "$*"; }
+# rmold [OPTIONS] <DIRECTORY>
+# Delete oldest files from DIRECTORY and keep the 5 (default) newest
+#  -r <AMOUNT FILES TO KEEP>
+rmold() {
+  local arg
+  local total
+  local line
+  local retain=5
+  local target
+  local hideOpt=
+
+  while getopts "hr:" arg ; do
+    case "${arg}" in
+      h) hideOpt="-A" ;;
+      r) [[ ${OPTARG} =~ [0-9]+ ]] && retain="${OPTARG}" || retain="" ;;
+      *) ;;
+    esac
+  done
+  shift "$((OPTIND-1))"; OPTIND=1
+
+  if [ -z "${retain}" ] ; then
+    error -e "Invalid retain option"
+    return 1
+  fi
+  target="${1:-}"
+
+  endIfEmpty target "No directory provided"
+  if [ ! -x "${target}" ] ; then
+    error -e "Cannot access ${target}"
+    return 1
+  fi
+
+  # shellcheck disable=SC2012 # Use find instead
+  total="$(ls ${hideOpt} -1 -- "${target}" | wc -l)"
+  if (( total <= retain )) ; then
+    info "Nothing to do"
+    return 0
+  fi
+
+  info    "Deleting $((total - retain)) oldest files in ${target}"
+  info -a "and retaining ${retain}."
+  exe cd "${target}"
+  # It is easier to sort with ls
+  # shellcheck disable=SC2012 # Use find instead
+  while IFS= read -r line; do
+    exe rm -f "${line}"
+  done < <(ls ${hideOpt} -rt1 "${target}" | head -$((total - retain)))
+}
 
 # saveReturn <ERRNO>
 # Function returns with <ERRNO> in case step wants additional evaluation
@@ -782,10 +840,11 @@ addConfMultiError() {
 # if all fails, a log file is created with the conflicts to be resolved by the user
 addConf() {
   local addConfBackup=
+  local echoOpt=()
   local confMode=""
   local transferCmd="echo"
 
-  while getopts "acfms" arg ; do
+  while getopts "acefms" arg ; do
     case "${arg}" in
       c) # create a new file
         addConfMultiError "${confMode}" && confMode="-c" ;;
@@ -795,6 +854,8 @@ addConf() {
         addConfMultiError "${confMode}" && confMode="-s" ;;
       m) # only add content to missing conf and warn user
         addConfMultiError "${confMode}" && confMode="-m" ;;
+      e) # Enable backslash escapes for echo
+        echoOpt+=("-e") ;;
       f) # choose if source is a file or text
         transferCmd="cat" ;;
       *) ;;
@@ -807,6 +868,8 @@ addConf() {
     exit 0
   fi
 
+  [[ "${transferCmd}" == "cat" ]] && echoOpt=()
+
   local source="${1:-}"
   local dest="${2:?}"
 
@@ -828,7 +891,7 @@ addConf() {
   if [[ ${confMode} != "-m" ]] ; then
     # try writing config directly if it doesn't exist
     if [ ! -f "$dest" ] ; then
-      "${transferCmd}" "${source}" > "${dest}"
+      "${transferCmd}" "${echoOpt[@]}" "${source}" > "${dest}"
       sqr::echo "ok"
       return 0
     fi
@@ -842,9 +905,9 @@ addConf() {
       if [ ! -f "${addConfBackup}" ] ; then
         cp -ar "${dest}" "${addConfBackup}"
         if [[ ${confMode} == "-c" ]] ; then
-          "${transferCmd}" "${source}" > "${dest}"
+          "${transferCmd}" "${echoOpt[@]}" "${source}" > "${dest}"
         else
-          "${transferCmd}" "${source}" >> "${dest}"
+          "${transferCmd}" "${echoOpt[@]}" "${source}" >> "${dest}"
         fi
         sqr::printf 'ok\n [i] %s\n' "Existing config saved to ${addConfBackup}"
         return 0