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 "$ax_common_sourced" ]; then
23 echo "Error ($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 " --errors|-e Generate email on errors only."
38 echo " --from|-f Email address of the sender of the email."
39 echo " --stderr-is-warning|-W Exit code indicates error; stderr is only warning."
40 echo " --subject|-s <subject> Subject for the email."
41 echo " --to|-t <address> Email address to send the email to."
43 echo "When no <command> is given, $NAME reads from standard input."
50 ax_error -l "Syntax error!"
55 if [[ -z "$proc_fd_works" ]]; then
56 ax_debug "Cleaning temporary files ..."
57 [[ -n "$buffer_file" ]] && rm -f "$buffer_file"
58 [[ -n "$error_file" ]] && rm -f "$error_file"
70 # Initialize internal state.
74 host=$(hostname -f 2>/dev/null || hostname)
78 # Some defaults (can be adjusted by command line parameters).
80 unset stderr_is_warning
82 from="${LOGNAME:-root} <${LOGNAME:-root}@$host>"
85 # Parse the command line ...
86 while [[ $# -gt 0 ]]; do
100 [[ $# -gt 0 ]] || syntax_error
108 [[ $# -gt 0 ]] || syntax_error
111 "--stderr-is-warning"|"-W")
115 # Ignore this switch for compatibility with an other
116 # "mail-wrapper" script. This is the default anyway!
120 [[ $# -gt 0 ]] || syntax_error
127 # Command to execute follows in command line.
134 # Initialize the "buffer file" on file handle #3. This file will store all
135 # output, stdout and stderr combined. The file is immediately unliked so that
136 # we can't leak stale files. Afterwards this script accesses the "buffer file"
137 # by its file descriptor only.
138 buffer_file=$(mktemp) \
139 || ax_abort -l "Failed to create buffer file: \"$buffer_file\"!"
140 ax_debug "buffer_file=\"$buffer_file\""
141 exec 3>"$buffer_file" \
142 || ax_abort -l "Failed to redirect FD #3 to buffer file!"
143 if [[ -n "$proc_fd_works" ]]; then
145 || ax_error -l "Failed to delete buffer file: \"$buffer_file\"!"
146 buffer_file="/dev/fd/3"
149 if [[ $# -gt 0 ]]; then
150 # Execute command and save output in buffer file.
151 # Use a sub-shell to not pollute our name space!
152 error_file=$(mktemp) \
153 || ax_abort -l "Failed to create error buffer file: \"$error_file\"!"
154 ax_debug "error_file=\"$error_file\""
155 exec 4>"$error_file" \
156 || ax_abort -l "Failed to redirect FD #4 to error file!"
157 if [[ -n "$proc_fd_works" ]]; then
159 || ax_error -l "Failed to delete error buffer file: \"$error_file\"!"
160 error_file="/dev/fd/4"
165 ax_debug "Running command \"$*\" ..."
167 "$@" 2>&1 1>&3 | tee "$error_file" >&3
168 echo "${PIPESTATUS[0]}"
171 # Read from stdin and save it to the buffer file.
172 error_file="/dev/null"
175 ax_debug "Reading from stdin ..."
176 while read -r line; do
178 || ax_abort -l "Failed to write to buffer file!"
183 ax_debug "exit_code=$exit_code"
185 declare -i count_all count_err
186 count_all=$(wc -l <"$buffer_file" || ax_abort -l "Failed to count buffer file!")
187 count_err=$(wc -l <"$error_file" || ax_abort -l "Failed to count error file!")
189 # Error or no error -- that's the question! An error is assumed when either the
190 # exit code of the command was non-zero or there was output to stderr.
191 # But when stderr_is_warning is set, messages on stderr result on a warning only!
192 if [[ $exit_code -ne 0 ]]; then
194 elif [[ $count_err -gt 0 ]]; then
195 [[ -n $stderr_is_warning ]] && error_level=1 || error_level=2
200 # Construct email subject ...
201 [[ -z "$subject" ]] && subject="$host: $job report"
202 if [[ "$error_level" -eq 0 ]]; then
203 subject="$subject - success"
204 elif [[ "$error_level" -eq 1 ]]; then
205 subject="$subject - WARNING!"
207 subject="$subject - ERROR!"
210 ax_debug "from=\"$from\""
211 ax_debug "to=\"$to\""
212 ax_debug "subject=$subject"
214 if [[ -n "$DEBUG" ]]; then
215 echo "--- stdout+stderr ---"
217 echo "--- stderr ---"
222 ax_debug "count_all=$count_all"
223 ax_debug "count_err=$count_err"
224 ax_debug "error_level=$error_level"
226 # No errors detected (exit code & stderr), and email should be sent on errors
227 # only: so exit early!
228 [[ "$error_level" -lt 2 && -n "$do_errors_only" ]] && exit $exit_code
230 # No error detected and no output at all: skip email, exit early:
231 [[ "$error_level" -eq 0 && $count_all -eq 0 ]] && exit $exit_code
233 # Build the report mail.
234 # Make sure to ignore all mail(1) configuration files, system wide /etc/mailrc
235 # (by using the "-n" option) as well as ~/.mailrc (by setting the MAILRC
236 # environment varialbe).
237 export MAILRC=/dev/null
241 echo " - Host: $host"
242 echo " - User: $(id -un)"
243 echo " - Exit code: $exit_code"
245 if [[ $# -gt 0 ]]; then
246 # A command name is known (not stdin), show it!
251 if [[ $count_err -gt 0 ]]; then
252 # Prefix mail with all error messages.
253 echo "Error summary:"
254 echo "-----------------------------------------------------------------------------"
256 || ax_abort -l "Failed to dump error file!"
257 echo "-----------------------------------------------------------------------------"
260 if [[ $count_all -ne $count_err ]]; then
261 # Show full output when different to "error output" only.
263 || ax_abort -l "Failed to dump buffer file!"
265 ) | mail -n -a "From: $from" -s "$subject" "$to" \
266 || ax_abort -l "Failed to send email to \"$to\"!"