log module

module/log.module.sh

@@ -0,0 +1,125 @@
+#!/bin/bash
+source /cis/core/base.module.sh
+
+
+
+# log.string values
+#  - values mandatory: "log" "this test"
+#
+# Logs the given values to stderr if _MODE is '--interactive'.
+# Additionally the input is written to the file '${_LOG_FILE_FULLNAME}', if it is defined.
+#
+# Custom line breaks are preserved,
+# backslash-escaped characters are interpreted (e.g. '\n' or '\t'),
+# but no line break is appended automatically. (see: log.line)
+function log.string() {
+    # Logverzeichnis bei Bedarf anlegen
+    if [[ "${_LOG_FILE_FULLNAME}" == /* ]]; then
+        mkdir -p "${_LOG_FILE_FULLNAME%/*}"
+        if [ "${_MODE}" == "--interactive" ]; then
+            printf -- "%b" "$*" >&2
+            printf -- "%b" "$*" >> "${_LOG_FILE_FULLNAME:?"Missing LOG_FILE_FULLNAME"}"
+        else
+            printf -- "%b" "$*" >> "${_LOG_FILE_FULLNAME:?"Missing LOG_FILE_FULLNAME"}"
+        fi
+    else
+        if [ "${_MODE}" == "--interactive" ]; then
+            printf -- "%b" "$*" >&2
+        fi
+    fi
+    return 0
+}
+
+
+
+# log.line values
+#  - values mandatory: "log" "this test"
+#
+# Logs the given values to stderr if _MODE is '--interactive'.
+# Additionally the input is written to the file '${_LOG_FILE_FULLNAME}', if it is defined.
+#
+# Custom line breaks are preserved,
+# backslash-escaped characters are interpreted (e.g. '\n' or '\t'),
+# and a line break is appended automatically (see: log.string).
+function log.line() {
+    # Logverzeichnis bei Bedarf anlegen
+    if [[ "${_LOG_FILE_FULLNAME}" == /* ]]; then
+        mkdir -p "${_LOG_FILE_FULLNAME%/*}"
+        if [ "${_MODE}" == "--interactive" ]; then
+            printf -- "%b\n" "$*" >&2
+            printf -- "%b\n" "$*" >> "${_LOG_FILE_FULLNAME:?"Missing LOG_FILE_FULLNAME"}"
+        else
+            printf -- "%b\n" "$*" >> "${_LOG_FILE_FULLNAME:?"Missing LOG_FILE_FULLNAME"}"
+        fi
+    else
+        if [ "${_MODE}" == "--interactive" ]; then
+            printf -- "%b\n" "$*" >&2
+        fi
+    fi
+    return 0
+}
+
+
+
+# log.success
+#
+# This function is meant to be uses in '&&' chain. So if the previous command was successful,
+# and a log file '${_LOG_FILE_FULLNAME}' is defined, then a closing line will be appended.
+# The appended line follows the monitoring convention 'OK' or 'OK#optional comment'.
+#
+# Additionally, the log file will be trimmed to the maximum number of lines defined in '${_LOG_MAX_LINES}'.
+function log.success() {
+    local -r _LOG_MAX_LINES_DEFAULT=100
+    local    _LOG_MAX_LINES="${_LOG_MAX_LINES:-${_LOG_MAX_LINES_DEFAULT}}"
+
+    # _LOG_MAX_LINES can be set globally
+    if ! [[ "$_LOG_MAX_LINES" =~ ^[0-9]+$ ]]; then
+        logln "WARNING: Invalid value _LOG_MAX_LINES. Fallback to default '${_LOG_MAX_LINES_DEFAULT}'."
+        _LOG_MAX_LINES="${_LOG_MAX_LINES_DEFAULT}"
+    fi
+
+    if [ -f "${_LOG_FILE_FULLNAME}" ]; then
+        printf -- "%b\n" "OK#Last update $(date "+%Y-%m-%d %H:%M:%S")" >> "${_LOG_FILE_FULLNAME}"
+
+        # Rolling window
+        local _TMP_FILE="${_LOG_FILE_FULLNAME}.tmp"
+        tail -n "${_LOG_MAX_LINES}" "${_LOG_FILE_FULLNAME}" > "${_TMP_FILE}" \
+            && mv "${_TMP_FILE}" "${_LOG_FILE_FULLNAME}"
+    fi
+    return 0
+}
+
+
+
+# log.fail
+#
+# This funtion is meant to be used at the end of a script in case of an failure.
+# If a log file '${_LOG_FILE_FULLNAME}' is defined, then a closing line will be appended.
+# The appended line follows the monitoring convention 'FAIL' or 'FAIL#optinal comment'.
+function log.fail() {
+    if [ -f "${_LOG_FILE_FULLNAME}" ]; then
+        printf -- "%b\n" "FAIL#Check ${_LOG_FILE_FULLNAME}" >> "${_LOG_FILE_FULLNAME}"
+    fi
+    return 0
+}
+
+
+
+# Check if this module was started correctly using source
+if [ "${BASH_SOURCE[0]}" == "${0}" ]; then
+    # Script was executed directly
+    echo "FAILURE: you are using this module 'log.module.sh' in a wrong way."
+    echo "    It is intended as a utility library and should not be called directly."
+    echo
+    echo "Usage: Call this module at the beginning of your script e.g. like this:"
+    echo
+    echo '    #!/bin/bash'
+    echo '    source /cis/core/base.module.sh'
+    echo
+    echo '    #Loads this module'
+    echo '    base.loadModule log'
+    echo
+    base.explain 'log' "${1}" "${2}"
+    echo
+    exit 1
+fi