3 # mail-wrapper -- Report results of a command by email
4 # Copyright (c)2017,2018 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 "$ax_common_sourced" ]; then
23 echo "Error ($NAME): \"ax-common.sh\" not found, aborting!" >&2
24 echo "Please install 'ax-unix', \"Alex' UNIX Tools & Scripts\", and try again."
27 unset dir ax_common ax_common_sourced
33 echo " $NAME [--help|--usage]"
34 echo " $NAME {parameters} [<command> [<arg> [<…>]]]"
36 echo " -C Use the \"C\" locale, no localized (error) messages."
37 echo " --dontfail|-n Don't return the error code of the command called."
38 echo " --errors|-e Generate email on errors only."
39 echo " --from|-f Email address of the sender of the email."
40 echo " --stderr-is-warning|-W Exit code indicates error; stderr is only warning."
41 echo " --subject|-s <subject> Subject for the email."
42 echo " --to|-t <address> Email address to send the email to."
44 echo "When no <command> is given, $NAME reads from standard input."
51 ax_error -l "Syntax error!"
56 if [[ -z "$proc_fd_works" ]]; then
57 ax_debug "Cleaning temporary files ..."
58 [[ -n "$buffer_file" ]] && rm -f "$buffer_file"
59 [[ -n "$error_file" ]] && rm -f "$error_file"
71 # Initialize internal state.
75 host=$(hostname -f 2>/dev/null || hostname)
79 # Some defaults (can be adjusted by command line parameters).
82 unset stderr_is_warning
84 from="${LOGNAME:-root} <${LOGNAME:-root}@$host>"
87 # Parse the command line ...
88 while [[ $# -gt 0 ]]; do
105 [[ $# -gt 0 ]] || syntax_error
113 [[ $# -gt 0 ]] || syntax_error
116 "--stderr-is-warning"|"-W")
120 # Ignore this switch for compatibility with an other
121 # "mail-wrapper" script. This is the default anyway!
125 [[ $# -gt 0 ]] || syntax_error
132 # Command to execute follows in command line.
139 # Initialize the "buffer file" on file handle #3. This file will store all
140 # output, stdout and stderr combined. The file is immediately unliked so that
141 # we can't leak stale files. Afterwards this script accesses the "buffer file"
142 # by its file descriptor only.
143 buffer_file=$(mktemp) \
144 || ax_abort -l "Failed to create buffer file: \"$buffer_file\"!"
145 ax_debug "buffer_file=\"$buffer_file\""
146 exec 3>"$buffer_file" \
147 || ax_abort -l "Failed to redirect FD #3 to buffer file!"
148 if [[ -n "$proc_fd_works" ]]; then
150 || ax_error -l "Failed to delete buffer file: \"$buffer_file\"!"
151 buffer_file="/dev/fd/3"
154 if [[ $# -gt 0 ]]; then
155 # Execute command and save output in buffer file.
156 # Use a sub-shell to not pollute our name space!
157 error_file=$(mktemp) \
158 || ax_abort -l "Failed to create error buffer file: \"$error_file\"!"
159 ax_debug "error_file=\"$error_file\""
160 exec 4>"$error_file" \
161 || ax_abort -l "Failed to redirect FD #4 to error file!"
162 if [[ -n "$proc_fd_works" ]]; then
164 || ax_error -l "Failed to delete error buffer file: \"$error_file\"!"
165 error_file="/dev/fd/4"
170 ax_debug "Running command \"$*\" ..."
172 "$@" 2>&1 1>&3 | tee "$error_file" >&3
173 echo "${PIPESTATUS[0]}"
176 # Read from stdin and save it to the buffer file.
177 error_file="/dev/null"
180 ax_debug "Reading from stdin ..."
181 while read -r line; do
183 || ax_abort -l "Failed to write to buffer file!"
188 ax_debug "exit_code=$exit_code"
190 declare -i count_all count_err
191 count_all=$(wc -l <"$buffer_file" || ax_abort -l "Failed to count buffer file!")
192 count_err=$(wc -l <"$error_file" || ax_abort -l "Failed to count error file!")
194 # Error or no error -- that's the question! An error is assumed when either the
195 # exit code of the command was non-zero or there was output to stderr.
196 # But when stderr_is_warning is set, messages on stderr result on a warning only!
197 if [[ $exit_code -ne 0 ]]; then
199 elif [[ $count_err -gt 0 ]]; then
200 [[ -n $stderr_is_warning ]] && error_level=1 || error_level=2
205 # Construct email subject ...
206 [[ -z "$subject" ]] && subject="$host: $job report"
207 if [[ "$error_level" -eq 0 ]]; then
208 subject="$subject - success"
209 elif [[ "$error_level" -eq 1 ]]; then
210 subject="$subject - WARNING!"
212 subject="$subject - ERROR!"
215 ax_debug "from=\"$from\""
216 ax_debug "to=\"$to\""
217 ax_debug "subject=$subject"
219 if [[ -n "$DEBUG" ]]; then
220 echo "--- stdout+stderr ---"
222 echo "--- stderr ---"
227 ax_debug "count_all=$count_all"
228 ax_debug "count_err=$count_err"
229 ax_debug "error_level=$error_level"
231 # No errors detected (exit code & stderr), and email should be sent on errors
232 # only: so exit early!
233 [[ "$error_level" -lt 2 && -n "$do_errors_only" ]] && exit $exit_code
235 # No error detected and no output at all: skip email, exit early:
236 [[ "$error_level" -eq 0 && $count_all -eq 0 ]] && exit $exit_code
238 # Build the report mail.
239 # Make sure to ignore all mail(1) configuration files, system wide /etc/mailrc
240 # (by using the "-n" option) as well as ~/.mailrc (by setting the MAILRC
241 # environment varialbe).
242 export MAILRC=/dev/null
246 echo " - Host: $host"
247 echo " - User: $(id -un)"
248 echo " - Exit code: $exit_code"
250 if [[ $# -gt 0 ]]; then
251 # A command name is known (not stdin), show it!
256 if [[ $count_err -gt 0 ]]; then
257 # Prefix mail with all error messages.
258 echo "Error summary:"
259 echo "-----------------------------------------------------------------------------"
261 || ax_abort -l "Failed to dump error file!"
262 echo "-----------------------------------------------------------------------------"
265 if [[ $count_all -ne $count_err ]]; then
266 # Show full output when different to "error output" only.
268 || ax_abort -l "Failed to dump buffer file!"
270 ) | mail -n -a "From: $from" -s "$subject" "$to" \
271 || ax_abort -l "Failed to send email to \"$to\"!"
273 [[ -n "$dont_fail" ]] && exit 0 || exit $exit_code