funcs/gsu

   1 # gsu -- the global subcommand utility
   2 # (C) 2006-2007 Andre Noll
   3
   4 gsu_init_errors()
   5 {
   6         gsu_errors="
   7 GSU_SUCCESS                     success
   8 E_GSU_BAD_COMMAND               invalid command
   9 E_GSU_NOT_A_NUMBER              not a number
  10 $gsu_errors
  11 "
  12         local a b i=0
  13         while read a b; do
  14                 if test -z "$a"; then
  15                         continue
  16                 fi
  17                 #echo "a:$a,  b: $b"
  18                 gsu_error_txt[i]="$b"
  19                 eval $a=$i
  20                 i=$(($i + 1))
  21         done << EOF
  22         $gsu_errors
  23 EOF
  24 }
  25 export -f gsu_init_errors
  26
  27 # check if $1 is a number
  28 gsu_is_a_number()
  29 {
  30         result="$1"
  31         if test "$1" -eq "$1" &> /dev/null; then
  32                 ret=$GSU_SUCCESS
  33         else
  34                 ret=-$E_GSU_NOT_A_NUMBER
  35         fi
  36 }
  37 export -f gsu_is_a_number
  38
  39 gsu_short_msg()
  40 {
  41         echo "$1" 1>&2
  42 }
  43 export -f gsu_short_msg
  44
  45 gsu_msg()
  46 {
  47         gsu_short_msg "$gsu_self: $1"
  48 }
  49 export -f gsu_msg
  50
  51 gsu_date_msg()
  52 {
  53         gsu_short_msg "$gsu_self $(date): $1"
  54 }
  55 export -f gsu_date_msg
  56
  57 gsu_banner_msg()
  58 {
  59         local txt="*** $gsu_self --"
  60         if test -z "$gsu_banner_txt"; then
  61                 txt="$txt set \$gsu_banner_txt to customize this message"
  62         else
  63                 txt="$txt $gsu_banner_txt"
  64         fi
  65         gsu_short_msg "$txt ***"
  66 }
  67 export -f gsu_banner_msg
  68
  69 gsu_err_msg()
  70 {
  71         local txt="$result" err
  72
  73         gsu_is_a_number "$ret"
  74         if test $ret -lt 0; then
  75                 gsu_msg "unknown error ($ret:$txt)"
  76                 exit 1
  77         fi
  78         if test $result -ge 0; then
  79                 gsu_msg "unknown error ($result:$txt)"
  80                 exit 1
  81         fi
  82         err=$((0 - $result))
  83         if test -n "$txt"; then
  84                 txt="$txt: ${gsu_error_txt[$err]}"
  85         else
  86                 txt="${gsu_error_txt[$err]}"
  87         fi
  88         gsu_msg "$txt"
  89 }
  90 export -f gsu_err_msg
  91
  92 gsu_usage()
  93 {
  94         gsu_short_msg "Usage: $gsu_self command [options]"
  95 }
  96 export -f gsu_usage
  97
  98 gsu_available_commands()
  99 {
 100         result="$( (printf "help\nman\n"; grep "^com_[a-z_]\+()" $0) \
 101                 | sed -e 's/^com_//' -e 's/()//' \
 102                 | sort \
 103                 | tr '\n' ' ')"
 104         ret=$GSU_SUCCESS
 105 }
 106 export -f gsu_available_commands
 107
 108 gsu_print_available_commands()
 109 {(
 110         local i count
 111         gsu_short_msg "Available commands:"
 112         for i in $gsu_cmds; do
 113                 printf "$i"
 114                 count=$(($count + 1))
 115                 if test $(($count % 4)) -eq 0; then
 116                         echo
 117                 else
 118                         printf "\t"
 119                         if test ${#i} -lt 8; then
 120                                 printf "\t"
 121                         fi
 122                 fi
 123         done
 124         echo
 125 ) 2>&1
 126 }
 127 export -f gsu_print_available_commands
 128
 129 export gsu_man_txt="
 130 Print the manual.
 131
 132 Usage: man"
 133
 134 com_man()
 135 {
 136         local equal_signs="=================================================="
 137         local minus_signs="--------------------------------------------------"
 138         local tilde_signs="~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
 139         local com num
 140
 141         echo "$gsu_self (_${gsu_banner_txt}_) manual"
 142         echo "${equal_signs:0:${#gsu_self} + ${#gsu_banner_txt} + 16}"
 143         echo
 144
 145         sed -e '1,/^#\{70,\}/d' -e '/^#\{70,\}/,$d' $0 -e 's/^# *//'
 146         echo "----"
 147         echo
 148         echo "$gsu_self usage"
 149         echo "${minus_signs:0:${#gsu_self} + 6}"
 150         printf "\t"
 151         gsu_usage 2>&1
 152         echo "Each command has its own set of options as described below."
 153         echo
 154         echo "----"
 155         echo
 156         echo "Available commands:"
 157
 158         gsu_available_commands
 159         for com in $result; do
 160                 num=${#com}
 161                 if test $num -lt 4; then
 162                         num=4
 163                 fi
 164                 echo "${minus_signs:0:$num}"
 165                 echo "$com"
 166                 echo "${minus_signs:0:$num}"
 167                 $0 help $com
 168                 echo
 169         done
 170         ret=$GSU_SUCCESS
 171 }
 172 export -f com_man
 173
 174 export gsu_help_txt="
 175 Print online help.
 176
 177 Usage: help [command]
 178
 179 Without arguments, print the list of available commands. Otherwise,
 180 print the help text for the given command."
 181
 182 com_help()
 183 {
 184         local a b
 185         if test -z "$1"; then
 186                 gsu_banner_msg 2>&1
 187                 gsu_usage 2>&1
 188                 # sed is magic, baby
 189                 (printf "com_help()\n$gsu_help_txt" | head -n 4; echo "--"
 190                 printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
 191
 192                 grep -A 2 "^com_\([a-zA-Z_0-9]\+\)()" $0) \
 193                         | grep -v -- '--' \
 194                         | sed -e '/^com_\([a-zA-Z_0-9]\+\)()/bs' \
 195                                 -e 'H;$!d;x;s/\n//g;b' \
 196                                 -e :s \
 197                                 -e 'x;s/\n//g;${p;x;}' \
 198                         | sed -e 's/^com_\([a-zA-Z_0-9]\+\)()#*/\1\t/' \
 199                         | sort \
 200                         | while read a b; do
 201                                 printf "$a\t"
 202                                 if test ${#a} -lt 8; then
 203                                         printf "\t"
 204                                 fi
 205                                 echo "$b"
 206                         done
 207                 echo
 208                 echo "Try $gsu_self help <command> for info on <command>."
 209                 ret=$GSU_SUCCESS
 210                 return
 211         fi
 212         if test "$1" = "help"; then
 213                 echo "$gsu_help_txt"
 214                 ret=$GSU_SUCCESS
 215                 return
 216         fi
 217         if test "$1" = "man"; then
 218                 echo "$gsu_man_txt"
 219                 ret=$GSU_SUCCESS
 220                 return
 221         fi
 222         ret=$GSU_SUCCESS
 223         if grep -q "^com_$1()" $0; then
 224                 sed -e "1,/com_$1()/d" -e '/^{/,$d' -e 's/^## *//' $0
 225                 return
 226         fi
 227         gsu_print_available_commands
 228         result="$1"
 229         ret=-$E_GSU_BAD_COMMAND
 230 }
 231 export -f com_help
 232
 233 gsu()
 234 {
 235         local i
 236
 237         gsu_self="$(basename $0)"
 238         gsu_init_errors
 239         gsu_available_commands
 240         gsu_cmds="$result"
 241         if test $# -eq 0; then
 242                 gsu_usage
 243                 gsu_print_available_commands
 244                 exit 1
 245         fi
 246         arg="$1"
 247         shift
 248         for i in $gsu_cmds; do
 249                 if test "$arg" = "$i"; then
 250                         com_$arg "$@"
 251                         if test $ret -lt 0; then
 252                                 gsu_err_msg
 253                                 exit 1
 254                         fi
 255                         exit 0
 256                 fi
 257         done
 258         ret=-$E_GSU_BAD_COMMAND
 259         result="$arg"
 260         gsu_err_msg
 261         gsu_print_available_commands
 262         exit 1
 263 }
 264 # no need to export this