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 $gsu_errors
  14 "
  15         local a b i=0
  16         while read a b; do
  17                 if test -z "$a"; then
  18                         continue
  19                 fi
  20                 #echo "a:$a,  b: $b"
  21                 gsu_error_txt[i]="$b"
  22                 eval $a=$i
  23                 i=$(($i + 1))
  24         done << EOF
  25         $gsu_errors
  26 EOF
  27 }
  28 export -f _gsu_init_errors
  29
  30 # check if $1 is a number
  31 gsu_is_a_number()
  32 {
  33         result="$1"
  34         if test "$1" -eq "$1" &> /dev/null; then
  35                 ret=$GSU_SUCCESS
  36         else
  37                 ret=-$E_GSU_NOT_A_NUMBER
  38         fi
  39 }
  40 export -f gsu_is_a_number
  41
  42 gsu_short_msg()
  43 {
  44         echo "$1" 1>&2
  45 }
  46 export -f gsu_short_msg
  47
  48 gsu_msg()
  49 {
  50         gsu_short_msg "$_gsu_self: $1"
  51 }
  52 export -f gsu_msg
  53
  54 gsu_date_msg()
  55 {
  56         gsu_short_msg "$_gsu_self $(date): $1"
  57 }
  58 export -f gsu_date_msg
  59
  60 _gsu_banner_msg()
  61 {
  62         local txt="*** $_gsu_self --"
  63         if test -z "$gsu_banner_txt"; then
  64                 txt="$txt set \$gsu_banner_txt to customize this message"
  65         else
  66                 txt="$txt $gsu_banner_txt"
  67         fi
  68         gsu_short_msg "$txt ***"
  69 }
  70 export -f _gsu_banner_msg
  71
  72 gsu_err_msg()
  73 {
  74         local txt="$result" err
  75
  76         gsu_is_a_number "$ret"
  77         if test $ret -lt 0; then
  78                 gsu_msg "unknown error ($ret:$txt)"
  79                 exit 1
  80         fi
  81         if test $result -ge 0; then
  82                 gsu_msg "unknown error ($result:$txt)"
  83                 exit 1
  84         fi
  85         err=$((0 - $result))
  86         if test -n "$txt"; then
  87                 txt="$txt: ${gsu_error_txt[$err]}"
  88         else
  89                 txt="${gsu_error_txt[$err]}"
  90         fi
  91         gsu_msg "$txt"
  92 }
  93 export -f gsu_err_msg
  94
  95 _gsu_usage()
  96 {
  97         gsu_short_msg "Usage: $_gsu_self command [options]"
  98 }
  99 export -f _gsu_usage
 100
 101 _gsu_available_commands()
 102 {
 103         result="$( (printf "help\nman\n"; grep "^com_[a-z_]\+()" $0) \
 104                 | sed -e 's/^com_//' -e 's/()//' \
 105                 | sort \
 106                 | tr '\n' ' ')"
 107         ret=$GSU_SUCCESS
 108 }
 109 export -f _gsu_available_commands
 110
 111 _gsu_print_available_commands()
 112 {(
 113         local i count
 114         gsu_short_msg "Available commands:"
 115         for i in $gsu_cmds; do
 116                 printf "$i"
 117                 count=$(($count + 1))
 118                 if test $(($count % 4)) -eq 0; then
 119                         echo
 120                 else
 121                         printf "\t"
 122                         if test ${#i} -lt 8; then
 123                                 printf "\t"
 124                         fi
 125                 fi
 126         done
 127         echo
 128 ) 2>&1
 129 }
 130 export -f _gsu_print_available_commands
 131
 132 export gsu_man_txt="
 133 Print the manual.
 134
 135 Usage: man"
 136
 137 com_man()
 138 {
 139         local equal_signs="=================================================="
 140         local minus_signs="--------------------------------------------------"
 141         local com num
 142
 143         echo "$_gsu_self (_${gsu_banner_txt}_) manual"
 144         echo "${equal_signs:0:${#_gsu_self} + ${#gsu_banner_txt} + 16}"
 145         echo
 146
 147         sed -e '1,/^#\{70,\}/d' -e '/^#\{70,\}/,$d' $0 -e 's/^# *//'
 148         echo "----"
 149         echo
 150         echo "$_gsu_self usage"
 151         echo "${minus_signs:0:${#_gsu_self} + 6}"
 152         printf "\t"
 153         _gsu_usage 2>&1
 154         echo "Each command has its own set of options as described below."
 155         echo
 156         echo "----"
 157         echo
 158         echo "Available commands:"
 159
 160         _gsu_available_commands
 161         for com in $result; do
 162                 num=${#com}
 163                 if test $num -lt 4; then
 164                         num=4
 165                 fi
 166                 echo "${minus_signs:0:$num}"
 167                 echo "$com"
 168                 echo "${minus_signs:0:$num}"
 169                 $0 help $com
 170                 echo
 171         done
 172         ret=$GSU_SUCCESS
 173 }
 174 export -f com_man
 175
 176 export gsu_help_txt="
 177 Print online help.
 178
 179 Usage: help [command]
 180
 181 Without arguments, print the list of available commands. Otherwise,
 182 print the help text for the given command."
 183
 184 com_help()
 185 {
 186         local a b
 187         if test -z "$1"; then
 188                 _gsu_banner_msg 2>&1
 189                 _gsu_usage 2>&1
 190                 # sed is magic, baby
 191                 (printf "com_help()\n$gsu_help_txt" | head -n 4; echo "--"
 192                 printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
 193
 194                 grep -A 2 "^com_\([a-zA-Z_0-9]\+\)()" $0) \
 195                         | grep -v -- '--' \
 196                         | sed -e '/^com_\([a-zA-Z_0-9]\+\)()/bs' \
 197                                 -e 'H;$!d;x;s/\n//g;b' \
 198                                 -e :s \
 199                                 -e 'x;s/\n//g;${p;x;}' \
 200                         | sed -e 's/^com_\([a-zA-Z_0-9]\+\)()#*/\1\t/' \
 201                         | sort \
 202                         | while read a b; do
 203                                 printf "$a\t"
 204                                 if test ${#a} -lt 8; then
 205                                         printf "\t"
 206                                 fi
 207                                 echo "$b"
 208                         done
 209                 echo
 210                 echo "Try $_gsu_self help <command> for info on <command>."
 211                 ret=$GSU_SUCCESS
 212                 return
 213         fi
 214         if test "$1" = "help"; then
 215                 echo "$gsu_help_txt"
 216                 ret=$GSU_SUCCESS
 217                 return
 218         fi
 219         if test "$1" = "man"; then
 220                 echo "$gsu_man_txt"
 221                 ret=$GSU_SUCCESS
 222                 return
 223         fi
 224         ret=$GSU_SUCCESS
 225         if grep -q "^com_$1()" $0; then
 226                 sed -e "1,/com_$1()/d" -e '/^{/,$d' -e 's/^## *//' $0
 227                 return
 228         fi
 229         _gsu_print_available_commands
 230         result="$1"
 231         ret=-$E_GSU_BAD_COMMAND
 232 }
 233 export -f com_help
 234
 235 _gsu_init_config()
 236 {
 237         local name val default_val required ty comment
 238
 239         # set default values
 240         while read name default_val required ty comment; do
 241                 if test -z "$name"; then
 242                         continue
 243                 fi
 244                 eval ${gsu_self}_$name="$default_val"
 245         done << EOF
 246         $gsu_config_vars
 247 EOF
 248         result="$HOME/.${gsu_self}rc"
 249         # overwrite by custom configuration
 250         if [ -r "$result" ]; then
 251                 ret=-$E_GSU_SOURCE
 252                 if ! . "$result"; then
 253                         gsu_err_msg
 254                         exit 1
 255                 fi
 256         fi
 257         while read name default_val required ty comment; do
 258                 [ -z "$name" ] && continue
 259                 eval val="\$$name"
 260                 # abort if any required config var remains unset
 261                 ret=-$_E_GSU_CONFIG
 262                 if [ "$val" = "-" -a "$required" = "required" ]; then
 263                         result="$name"
 264                         gsu_err_msg
 265                         exit 1
 266                 fi
 267                 if [ $ty == "number" ]; then
 268                         gsu_is_a_number "$val"
 269                         if [ $ret -lt 0];  then
 270                                 gsu_err_msg
 271                                 exit 1
 272                         fi
 273                 fi
 274                 eval export ${gsu_self}_$name
 275         done << EOF
 276         $config_vars
 277 EOF
 278 }
 279 export -f _gsu_init_config
 280
 281 gsu()
 282 {
 283         local i
 284
 285         _gsu_self="$(basename $0)"
 286         _gsu_init_errors
 287         _gsu_init_config
 288         _gsu_available_commands
 289         gsu_cmds="$result"
 290         if test $# -eq 0; then
 291                 _gsu_usage
 292                 _gsu_print_available_commands
 293                 exit 1
 294         fi
 295         arg="$1"
 296         shift
 297         for i in $gsu_cmds; do
 298                 if test "$arg" = "$i"; then
 299                         com_$arg "$@"
 300                         if test $ret -lt 0; then
 301                                 gsu_err_msg
 302                                 exit 1
 303                         fi
 304                         exit 0
 305                 fi
 306         done
 307         ret=-$E_GSU_BAD_COMMAND
 308         result="$arg"
 309         gsu_err_msg
 310         _gsu_print_available_commands
 311         exit 1
 312 }
 313 export -f gsu