3 # mail-wrapper -- Report results of a command by email
4 # Copyright (c)2017 Alexander Barton (alex@barton.de)
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
14 # Include "ax-common.sh":
16 for dir in "$HOME/lib" "$HOME/.ax" /usr/local /opt/ax /usr; do
17 [ -z "$ax_common_sourced" ] || break
18 ax_common="${dir}/lib/ax/ax-common.sh"
19 # shellcheck source=/usr/local/lib/ax/ax-common.sh
20 [ -r "$ax_common" ] && . "$ax_common"
22 if [ -z "$ax_common_sourced" ]; then
23 echo "Error ($(basename "$0")): \"ax-common.sh\" not found, aborting!"
24 echo "Please install 'ax-unix', \"Alex' UNIX Tools & Scripts\", and try again."
27 unset dir ax_common ax_common_sourced
32 echo " $NAME [--help|--usage]" >&2
33 echo " $NAME {parameters} [<command> [<arg> [<…>]]]" >&2
35 echo " -C Use the \"C\" locale, no localized (error) messages." >&2
36 echo " --errors|-e Generate email on errors only." >&2
37 echo " --from|-f Email address of the sender of the email." >&2
38 echo " --subject|-s <subject> Subject for the email." >&2
39 echo " --to|-t <address> Email address to send the email to." >&2
41 echo "When no <command> is given, $NAME reads from standard input." >&2
47 ax_error -l "Syntax error!"
51 # Initialize internal state.
53 host=$(hostname -f 2>/dev/null || hostname)
55 # Some defaults (can be adjusted by command line parameters).
58 from="${LOGNAME:-root} <${LOGNAME:-root}@$host>"
61 # Parse the command line ...
62 while [[ $# -gt 0 ]]; do
76 [[ $# -gt 0 ]] || syntax_error
84 [[ $# -gt 0 ]] || syntax_error
89 [[ $# -gt 0 ]] || syntax_error
96 # Command to execute follows in command line.
103 # Initialize the "buffer file" on file handle #3. This file will store all
104 # output, stdout and stderr combined. The file is immediately unliked so that
105 # we can't leak stale files. Afterwards this script accesses the "buffer file"
106 # by its file descriptor only.
107 buffer_file=$(mktemp) \
108 || ax_abort -l "Failed to create buffer file: \"$buffer_file\"!"
109 ax_debug "buffer_file=\"$buffer_file\""
110 exec 3>"$buffer_file" \
111 || ax_abort -l "Failed to redirect FD #3 to buffer file!"
113 || ax_error -l "Failed to delete buffer file: \"$buffer_file\"!"
114 buffer_file="/dev/fd/3"
116 if [[ $# -gt 0 ]]; then
117 # Execute command and save output in buffer file.
118 # Use a sub-shell to not pollute our name space!
119 error_file=$(mktemp) \
120 || ax_abort -l "Failed to create error buffer file: \"$error_file\"!"
121 ax_debug "error_file=\"$error_file\""
122 exec 4>"$error_file" \
123 || ax_abort -l "Failed to redirect FD #4 to error file!"
125 || ax_error -l "Failed to delete error buffer file: \"$error_file\"!"
126 error_file="/dev/fd/4"
130 ax_debug "Running command \"$*\" ..."
132 "$@" 2>&1 1>&3 | tee "$error_file" >&3
133 echo "${PIPESTATUS[0]}"
136 # Read from stdin and save it to the buffer file.
137 error_file="/dev/null"
140 ax_debug "Reading from stdin ..."
141 while read -r line; do
143 || ax_abort -l "Failed to write to buffer file!"
148 ax_debug "exit_code=$exit_code"
150 count_all=$(wc -l <"$buffer_file" || ax_abort -l "Failed to count buffer file!")
151 count_err=$(wc -l <"$error_file" || ax_abort -l "Failed to count error file!")
153 # Error or no error -- that's the question! An error is assumed when either the
154 # exit code of the command was non-zero or there was output to stderr.
155 [[ $count_err -gt 0 || $exit_code -ne 0 ]] && is_error=1
157 # Construct email subject ...
158 [[ -z "$subject" ]] && subject="$host: $job report"
159 [[ -n "$is_error" ]] && subject="$subject - ERROR!" || subject="$subject - success"
161 ax_debug "from=\"$from\""
162 ax_debug "to=\"$to\""
163 ax_debug "subject=$subject"
165 if [[ -n "$DEBUG" ]]; then
166 echo "--- stdout+stderr ---"
168 echo "--- stderr ---"
173 ax_debug "count_all=$count_all"
174 ax_debug "count_err=$count_err"
175 ax_debug "is_error=$is_error"
177 # No errors detected (exit code & stderr), and email should be sent on errors
178 # only: so exit early!
179 [[ -z "$is_error" && -n "$do_errors_only" ]] && exit $exit_code
181 # No error detected and no output at all: skip email, exit early:
182 [[ -z "$is_error" && $count_all -eq 0 ]] && exit $exit_code
184 # Build the report mail.
185 # Make sure to ignore all mail(1) configuration files, system wide /etc/mailrc
186 # (by using the "-n" option) as well as ~/.mailrc (by setting the MAILRC
187 # environment varialbe).
188 export MAILRC=/dev/null
192 echo " - Host: $host"
193 echo " - User: $(id -un)"
194 echo " - Exit code: $exit_code"
196 if [[ $# -gt 0 ]]; then
197 # A command name is known (not stdin), show it!
202 if [[ $count_err -gt 0 ]]; then
203 # Prefix mail with all error messages.
204 echo "Error summary:"
205 echo "-----------------------------------------------------------------------------"
207 || ax_abort -l "Failed to dump error file!"
208 echo "-----------------------------------------------------------------------------"
211 if [[ $count_all -ne $count_err ]]; then
212 # Show full output when different to "error output" only.
214 || ax_abort -l "Failed to dump buffer file!"
216 ) | mail -n -a "From: $from" -s "$subject" "$to" \
217 || ax_abort -l "Failed to send email to \"$to\"!"