Priliminary version of gsu2.
[gsu.git] / funcs / gsu
1 #!/bin/sh
2 # gsu -- the global subcommand utility
3 # (C) 2006-2009 Andre Noll
4
5 _gsu_init_errors()
6 {
7 gsu_errors="
8 GSU_SUCCESS success
9 E_GSU_BAD_COMMAND invalid command
10 E_GSU_NOT_A_NUMBER not a number
11 E_GSU_SOURCE error in config file
12 E_GSU_CONFIG bad/missing config file option
13 E_GSU_BAD_CONFIG_VAR invalid config variable
14 E_GSU_NEED_VALUE value required but not given
15 E_GSU_BAD_BOOL bad value for boolian option
16 E_GSU_BAD_OPTION_TYPE invalid option type
17 E_NO_DEFAULT missing default value
18 $gsu_errors
19 "
20 local a b i=0
21 while read a b; do
22 if test -z "$a"; then
23 continue
24 fi
25 #echo "a:$a, b: $b"
26 gsu_error_txt[i]="$b"
27 eval $a=$i
28 i=$(($i + 1))
29 done << EOF
30 $gsu_errors
31 EOF
32 }
33 export -f _gsu_init_errors
34
35 # check if $1 is a number
36 gsu_is_a_number()
37 {
38 result="$1"
39 if test "$1" -eq "$1" &> /dev/null; then
40 ret=$GSU_SUCCESS
41 else
42 ret=-$E_GSU_NOT_A_NUMBER
43 fi
44 }
45 export -f gsu_is_a_number
46
47 gsu_short_msg()
48 {
49 echo "$1" 1>&2
50 }
51 export -f gsu_short_msg
52
53 gsu_msg()
54 {
55 gsu_short_msg "$_gsu_self: $1"
56 }
57 export -f gsu_msg
58
59 gsu_date_msg()
60 {
61 gsu_short_msg "$_gsu_self $(date): $1"
62 }
63 export -f gsu_date_msg
64
65 _gsu_banner_msg()
66 {
67 local txt="*** $_gsu_self --"
68 if test -z "$gsu_banner_txt"; then
69 txt="$txt set \$gsu_banner_txt to customize this message"
70 else
71 txt="$txt $gsu_banner_txt"
72 fi
73 gsu_short_msg "$txt ***"
74 }
75 export -f _gsu_banner_msg
76
77 gsu_err_msg()
78 {
79 local txt="$result" err
80
81 gsu_is_a_number "$ret"
82 if test $ret -lt 0; then
83 gsu_msg "unknown error ($ret:$txt)"
84 exit 1
85 fi
86 if test $result -ge 0; then
87 gsu_msg "unknown error ($result:$txt)"
88 exit 1
89 fi
90 err=$((0 - $result))
91 if test -n "$txt"; then
92 txt="$txt: ${gsu_error_txt[$err]}"
93 else
94 txt="${gsu_error_txt[$err]}"
95 fi
96 gsu_msg "$txt"
97 }
98 export -f gsu_err_msg
99
100 _gsu_usage()
101 {
102 gsu_short_msg "Usage: $_gsu_self command [options]"
103 }
104 export -f _gsu_usage
105
106 _gsu_available_commands()
107 {
108 result="$( (printf "help\nman\nprefs\n"; grep "^com_[a-z_]\+()" $0) \
109 | sed -e 's/^com_//' -e 's/()//' \
110 | sort \
111 | tr '\n' ' ')"
112 ret=$GSU_SUCCESS
113 }
114 export -f _gsu_available_commands
115
116 _gsu_print_available_commands()
117 {(
118 local i count
119 gsu_short_msg "Available commands:"
120 for i in $gsu_cmds; do
121 printf "$i"
122 count=$(($count + 1))
123 if test $(($count % 4)) -eq 0; then
124 echo
125 else
126 printf "\t"
127 if test ${#i} -lt 8; then
128 printf "\t"
129 fi
130 fi
131 done
132 echo
133 ) 2>&1
134 }
135 export -f _gsu_print_available_commands
136
137 export gsu_prefs_txt="
138 Print the current preferences.
139
140 Usage: prefs
141
142 Print out a list of all cmt config variables, together with their current value
143 and the default value."
144 com_prefs()
145 {
146 local i
147
148 for ((i=0; i < ${#gsu_options[@]}; i++)); do
149 local name= option_type= default_value= required=
150 local description= help_text=
151 eval "${gsu_options[$i]}"
152 eval val='"$'${gsu_name}_$name'"'
153 case "$required" in
154 true|yes)
155 printf "# required"
156 ;;
157 *)
158 printf "# optional"
159 ;;
160 esac
161 printf " $option_type: $description"
162 if [[ "$required" != "yes" && "$required" != "true" ]]; then
163 printf " [$default_value]"
164 fi
165 echo
166 printf "$name=$val"
167 [[ "$val" == "$default_value" ]] && printf " # default"
168 echo
169 done
170 }
171 export -f com_prefs
172
173 export gsu_man_txt="
174 Print the manual.
175
176 Usage: man"
177
178 com_man()
179 {
180 local equal_signs="=================================================="
181 local minus_signs="--------------------------------------------------"
182 local com num
183
184 echo "$_gsu_self (_${gsu_banner_txt}_) manual"
185 echo "${equal_signs:0:${#_gsu_self} + ${#gsu_banner_txt} + 16}"
186 echo
187
188 sed -e '1,/^#\{70,\}/d' -e '/^#\{70,\}/,$d' $0 -e 's/^# *//'
189 echo "----"
190 echo
191 echo "$_gsu_self usage"
192 echo "${minus_signs:0:${#_gsu_self} + 6}"
193 printf "\t"
194 _gsu_usage 2>&1
195 echo "Each command has its own set of options as described below."
196 echo
197 echo "----"
198 echo
199 echo "Available commands:"
200
201 _gsu_available_commands
202 for com in $result; do
203 num=${#com}
204 if test $num -lt 4; then
205 num=4
206 fi
207 echo "${minus_signs:0:$num}"
208 echo "$com"
209 echo "${minus_signs:0:$num}"
210 $0 help $com
211 echo
212 done
213 ret=$GSU_SUCCESS
214 }
215 export -f com_man
216
217 export gsu_help_txt="
218 Print online help.
219
220 Usage: help [command]
221
222 Without arguments, print the list of available commands. Otherwise,
223 print the help text for the given command."
224
225 com_help()
226 {
227 local a b
228 if test -z "$1"; then
229 _gsu_banner_msg 2>&1
230 _gsu_usage 2>&1
231 # sed is magic, baby
232 (printf "com_help()\n$gsu_help_txt" | head -n 4; echo "--"
233 printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
234 printf "com_prefs()\n$gsu_prefs_txt" | head -n 4; echo "--"
235
236 grep -A 2 "^com_\([a-zA-Z_0-9]\+\)()" $0) \
237 | grep -v -- '--' \
238 | sed -e '/^com_\([a-zA-Z_0-9]\+\)()/bs' \
239 -e 'H;$!d;x;s/\n//g;b' \
240 -e :s \
241 -e 'x;s/\n//g;${p;x;}' \
242 | sed -e 's/^com_\([a-zA-Z_0-9]\+\)()#*/\1\t/' \
243 | sort \
244 | while read a b; do
245 printf "$a\t"
246 if test ${#a} -lt 8; then
247 printf "\t"
248 fi
249 echo "$b"
250 done
251 echo
252 echo "Try $_gsu_self help <command> for info on <command>."
253 ret=$GSU_SUCCESS
254 return
255 fi
256 if test "$1" = "help"; then
257 echo "$gsu_help_txt"
258 ret=$GSU_SUCCESS
259 return
260 fi
261 if test "$1" = "man"; then
262 echo "$gsu_man_txt"
263 ret=$GSU_SUCCESS
264 return
265 fi
266 if test "$1" = "prefs"; then
267 echo "$gsu_prefs_txt"
268 ret=$GSU_SUCCESS
269 return
270 fi
271 ret=$GSU_SUCCESS
272 if grep -q "^com_$1()" $0; then
273 sed -e "1,/com_$1()/d" -e '/^{/,$d' -e 's/^## *//' $0
274 return
275 fi
276 _gsu_print_available_commands
277 result="$1"
278 ret=-$E_GSU_BAD_COMMAND
279 }
280 export -f com_help
281
282 # internal gsu function that syntactically checks the gsu_options array
283 # for errors and parses the config file.
284 _gsu_check_options()
285 {
286 local i conf="${gsu_config_file:=$HOME/.$gsu_name.rc}"
287
288 [[ -r "$conf" ]] && source "$conf"
289
290 for ((i=0; i < ${#gsu_options[@]}; i++)); do
291 local name= option_type= default_value= required=
292 local description= help_text=
293 local val
294
295 eval "${gsu_options[$i]}"
296
297 # Check name. It must be non-empty and consist of [a-zA-Z_0-9]
298 # only. Moreover it must not start with [a-zA-Z].
299
300 ret=-$E_GSU_BAD_CONFIG_VAR
301 result="$name"
302 # bash's =~ works only for 3.2 and newer, so use grep
303 echo "$name" | grep '^[a-zA-Z][a-zA-Z_0123456789]*$' &> /dev/null;
304 [[ $? -ne 0 ]] && return
305
306 eval val='"'\$$name'"'
307 case "$required" in
308 true|yes)
309 ret=-$E_GSU_NEED_VALUE
310 result="$name"
311 [[ -z "$val" ]] && return
312 ;;
313 false|no)
314 ret=-$E_NO_DEFAULT
315 result="$name"
316 [[ -z "$default_value" ]] && return
317 ;;
318 *)
319 ret=-$E_GSU_BAD_BOOL
320 result="required: $required, name: $name, val: $val"
321 return
322 esac
323
324 eval ${gsu_name}_$name='"'${val:=$default_value}'"'
325
326 # Check option type. ATM, only num and string are supported
327 # Other types may be added without breaking compatibility
328 case "$option_type" in
329 string)
330 ;;
331 num)
332 gsu_is_a_number "$val"
333 [[ $ret -lt 0 ]] && return
334 ;;
335 *)
336 ret=-$E_BAD_OPTION_TYPE
337 result="$name/$option_type"
338 return
339 esac
340 done
341 ret=$GSU_SUCCESS
342 }
343 export -f _gsu_check_options
344
345 gsu()
346 {
347 local i
348
349 _gsu_self="$(basename $0)"
350 _gsu_init_errors
351 _gsu_check_options
352 if [[ "$ret" -lt 0 ]]; then
353 gsu_err_msg
354 exit 1
355 fi
356 _gsu_available_commands
357 gsu_cmds="$result"
358 if test $# -eq 0; then
359 _gsu_usage
360 _gsu_print_available_commands
361 exit 1
362 fi
363 arg="$1"
364 shift
365 for i in $gsu_cmds; do
366 if test "$arg" = "$i"; then
367 com_$arg "$@"
368 if test $ret -lt 0; then
369 gsu_err_msg
370 exit 1
371 fi
372 exit 0
373 fi
374 done
375 ret=-$E_GSU_BAD_COMMAND
376 result="$arg"
377 gsu_err_msg
378 _gsu_print_available_commands
379 exit 1
380 }
381 export -f gsu
382
383 # TODO: gsu_strerror: get error string