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                 [[ -n "$help_text" ]] && sed -e '/^[    ]*$/d; s/^[     ]*/#    /g' <<< "$help_text"
 167                 printf "$name=$val"
 168                 [[ "$val" == "$default_value" ]] && printf " # default"
 169                 echo
 170         done
 171 }
 172 export -f com_prefs
 173
 174 export gsu_man_txt="
 175 Print the manual.
 176
 177 Usage: man"
 178
 179 com_man()
 180 {
 181         local equal_signs="=================================================="
 182         local minus_signs="--------------------------------------------------"
 183         local com num
 184
 185         echo "$_gsu_self (_${gsu_banner_txt}_) manual"
 186         echo "${equal_signs:0:${#_gsu_self} + ${#gsu_banner_txt} + 16}"
 187         echo
 188
 189         sed -e '1,/^#\{70,\}/d' -e '/^#\{70,\}/,$d' $0 -e 's/^# *//'
 190         echo "----"
 191         echo
 192         echo "$_gsu_self usage"
 193         echo "${minus_signs:0:${#_gsu_self} + 6}"
 194         printf "\t"
 195         _gsu_usage 2>&1
 196         echo "Each command has its own set of options as described below."
 197         echo
 198         echo "----"
 199         echo
 200         echo "Available commands:"
 201
 202         _gsu_available_commands
 203         for com in $result; do
 204                 num=${#com}
 205                 if test $num -lt 4; then
 206                         num=4
 207                 fi
 208                 echo "${minus_signs:0:$num}"
 209                 echo "$com"
 210                 echo "${minus_signs:0:$num}"
 211                 $0 help $com
 212                 echo
 213         done
 214         ret=$GSU_SUCCESS
 215 }
 216 export -f com_man
 217
 218 export gsu_help_txt="
 219 Print online help.
 220
 221 Usage: help [command]
 222
 223 Without arguments, print the list of available commands. Otherwise,
 224 print the help text for the given command."
 225
 226 com_help()
 227 {
 228         local a b
 229         if test -z "$1"; then
 230                 _gsu_banner_msg 2>&1
 231                 _gsu_usage 2>&1
 232                 # sed is magic, baby
 233                 (printf "com_help()\n$gsu_help_txt" | head -n 4; echo "--"
 234                 printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
 235                 printf "com_prefs()\n$gsu_prefs_txt" | head -n 4; echo "--"
 236
 237                 grep -A 2 "^com_\([a-zA-Z_0-9]\+\)()" $0) \
 238                         | grep -v -- '--' \
 239                         | sed -e '/^com_\([a-zA-Z_0-9]\+\)()/bs' \
 240                                 -e 'H;$!d;x;s/\n//g;b' \
 241                                 -e :s \
 242                                 -e 'x;s/\n//g;${p;x;}' \
 243                         | sed -e 's/^com_\([a-zA-Z_0-9]\+\)()#*/\1\t/' \
 244                         | sort \
 245                         | while read a b; do
 246                                 printf "$a\t"
 247                                 if test ${#a} -lt 8; then
 248                                         printf "\t"
 249                                 fi
 250                                 echo "$b"
 251                         done
 252                 echo
 253                 echo "Try $_gsu_self help <command> for info on <command>."
 254                 ret=$GSU_SUCCESS
 255                 return
 256         fi
 257         if test "$1" = "help"; then
 258                 echo "$gsu_help_txt"
 259                 ret=$GSU_SUCCESS
 260                 return
 261         fi
 262         if test "$1" = "man"; then
 263                 echo "$gsu_man_txt"
 264                 ret=$GSU_SUCCESS
 265                 return
 266         fi
 267         if test "$1" = "prefs"; then
 268                 echo "$gsu_prefs_txt"
 269                 ret=$GSU_SUCCESS
 270                 return
 271         fi
 272         ret=$GSU_SUCCESS
 273         if grep -q "^com_$1()" $0; then
 274                 sed -e "1,/com_$1()/d" -e '/^{/,$d' -e 's/^## *//' $0
 275                 return
 276         fi
 277         _gsu_print_available_commands
 278         result="$1"
 279         ret=-$E_GSU_BAD_COMMAND
 280 }
 281 export -f com_help
 282
 283 # internal gsu function that syntactically checks the gsu_options array
 284 # for errors and parses the config file.
 285 _gsu_check_options()
 286 {
 287         local i conf="${gsu_config_file:=$HOME/.$gsu_name.rc}" val
 288
 289         for ((i=0; i < ${#gsu_options[@]}; i++)); do
 290                 eval "${gsu_options[$i]}"
 291                 eval val='"'\$$name'"'
 292                 eval orig_${gsu_config_var_prefix}_$name='"'${val}'"'
 293         done
 294
 295         [[ -r "$conf" ]] && source "$conf"
 296
 297         for ((i=0; i < ${#gsu_options[@]}; i++)); do
 298                 local name= option_type= default_value= required=
 299                 local description= help_text=
 300                 local val orig_val
 301
 302                 eval "${gsu_options[$i]}"
 303
 304
 305                 # Check name. It must be non-empty and consist of [a-zA-Z_0-9]
 306                 # only.  Moreover it must not start with [a-zA-Z].
 307
 308                 ret=-$E_GSU_BAD_CONFIG_VAR
 309                 result="$name"
 310                 # bash's =~ works only for 3.2 and newer, so use grep
 311                 echo "$name" | grep '^[a-zA-Z][a-zA-Z_0123456789]*$' &> /dev/null;
 312                 [[ $? -ne 0 ]] && return
 313
 314                 eval orig_val='"'\$orig_${gsu_config_var_prefix}_$name'"'
 315                 if [[ -z "$orig_val" ]]; then
 316                         eval val='"'\$$name'"'
 317                 else
 318                         val="$orig_val"
 319                 fi
 320                 case "$required" in
 321                 true|yes)
 322                         ret=-$E_GSU_NEED_VALUE
 323                         result="$name"
 324                         [[ -z "$val" ]] && return
 325                         ;;
 326                 false|no)
 327                         ;;
 328                 *)
 329                         ret=-$E_GSU_BAD_BOOL
 330                         result="required: $required, name: $name, val: $val"
 331                         return
 332                 esac
 333
 334                 eval ${gsu_config_var_prefix}_$name='"'${val:=$default_value}'"'
 335
 336                 # Check option type. ATM, only num and string are supported
 337                 # Other types may be added without breaking compatibility
 338                 case "$option_type" in
 339                 string)
 340                         ;;
 341                 num)
 342                         gsu_is_a_number "$val"
 343                         [[ $ret -lt 0 ]] && return
 344                         ;;
 345                 *)
 346                         ret=-$E_GSU_BAD_OPTION_TYPE
 347                         result="$name/$option_type"
 348                         return
 349                 esac
 350         done
 351         ret=$GSU_SUCCESS
 352 }
 353 export -f _gsu_check_options
 354
 355 gsu()
 356 {
 357         local i
 358
 359         _gsu_self="$(basename $0)"
 360         gsu_name="${gsu_name:=$_gsu_self}"
 361         gsu_config_var_prefix="${gsu_config_var_prefix:=$gsu_name}"
 362         _gsu_init_errors
 363         _gsu_check_options
 364         if [[ "$ret" -lt 0 ]]; then
 365                 if [[ "$1" != "help" && "$1" != "man" && "$1" != "prefs" ]]; then
 366                         gsu_err_msg
 367                         exit 1
 368                 fi
 369         fi
 370         _gsu_available_commands
 371         gsu_cmds="$result"
 372         if test $# -eq 0; then
 373                 _gsu_usage
 374                 _gsu_print_available_commands
 375                 exit 1
 376         fi
 377         arg="$1"
 378         shift
 379         for i in $gsu_cmds; do
 380                 if test "$arg" = "$i"; then
 381                         com_$arg "$@"
 382                         if test $ret -lt 0; then
 383                                 gsu_err_msg
 384                                 exit 1
 385                         fi
 386                         exit 0
 387                 fi
 388         done
 389         ret=-$E_GSU_BAD_COMMAND
 390         result="$arg"
 391         gsu_err_msg
 392         _gsu_print_available_commands
 393         exit 1
 394 }
 395 export -f gsu
 396
 397 # TODO: gsu_strerror: get error string