funcs/gsu

   1 #!/bin/bash
   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[$i]}"
 152                 eval val='"$'${gsu_config_var_prefix}_$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[$i]}"
 296
 297
 298                 # Check name. It must be non-empty and consist of [a-zA-Z_0-9]
 299                 # only.  Moreover it must not start with [a-zA-Z].
 300
 301                 ret=-$E_GSU_BAD_CONFIG_VAR
 302                 result="$name"
 303                 # bash's =~ works only for 3.2 and newer, so use grep
 304                 echo "$name" | grep '^[a-zA-Z][a-zA-Z_0123456789]*$' &> /dev/null;
 305                 [[ $? -ne 0 ]] && return
 306
 307                 eval val='"'\$$name'"'
 308                 case "$required" in
 309                 true|yes)
 310                         ret=-$E_GSU_NEED_VALUE
 311                         result="$name"
 312                         [[ -z "$val" ]] && return
 313                         ;;
 314                 false|no)
 315                         ;;
 316                 *)
 317                         ret=-$E_GSU_BAD_BOOL
 318                         result="required: $required, name: $name, val: $val"
 319                         return
 320                 esac
 321
 322                 eval ${gsu_config_var_prefix}_$name='"'${val:=$default_value}'"'
 323
 324                 # Check option type. ATM, only num and string are supported
 325                 # Other types may be added without breaking compatibility
 326                 case "$option_type" in
 327                 string)
 328                         ;;
 329                 num)
 330                         gsu_is_a_number "$val"
 331                         [[ $ret -lt 0 ]] && return
 332                         ;;
 333                 *)
 334                         ret=-$E_GSU_BAD_OPTION_TYPE
 335                         result="$name/$option_type"
 336                         return
 337                 esac
 338         done
 339         ret=$GSU_SUCCESS
 340 }
 341 export -f _gsu_check_options
 342
 343 gsu()
 344 {
 345         local i
 346
 347         _gsu_self="$(basename $0)"
 348         gsu_name="${gsu_name:=$_gsu_self}"
 349         gsu_config_var_prefix="${gsu_config_var_prefix:=$gsu_name}"
 350         _gsu_init_errors
 351         _gsu_check_options
 352         if [[ "$ret" -lt 0 ]]; then
 353                 if [[ "$1" != "help" && "$1" != "man" && "$1" != "prefs" ]]; then
 354                         gsu_err_msg
 355                         exit 1
 356                 fi
 357         fi
 358         _gsu_available_commands
 359         gsu_cmds="$result"
 360         if test $# -eq 0; then
 361                 _gsu_usage
 362                 _gsu_print_available_commands
 363                 exit 1
 364         fi
 365         arg="$1"
 366         shift
 367         for i in $gsu_cmds; do
 368                 if test "$arg" = "$i"; then
 369                         com_$arg "$@"
 370                         if test $ret -lt 0; then
 371                                 gsu_err_msg
 372                                 exit 1
 373                         fi
 374                         exit 0
 375                 fi
 376         done
 377         ret=-$E_GSU_BAD_COMMAND
 378         result="$arg"
 379         gsu_err_msg
 380         _gsu_print_available_commands
 381         exit 1
 382 }
 383 export -f gsu
 384
 385 # TODO: gsu_strerror: get error string