tg-shell.sh

   1 #!/bin/sh
   2 # TopGit wayback machine shell command
   3 # (C) 2017 Kyle J. McKay <mackyle@gmail.com>
   4 # All rights reserved
   5 # GPLv2
   6
   7 USAGE="\
   8 Usage: ${tgname:-tg} [...] -w [:]<tgtag> shell [--directory=<dirpath>] [-q] [--] [<arg>...]"
   9
  10 usage()
  11 {
  12         if [ "${1:-0}" != 0 ]; then
  13                 printf '%s\n' "$USAGE" >&2
  14         else
  15                 printf '%s\n' "$USAGE"
  16         fi
  17         exit ${1:-0}
  18 }
  19
  20 quote=
  21
  22 while [ $# -gt 0 ]; do case "$1" in
  23         -h|--help|--directory|--directory=*)
  24                 usage
  25                 ;;
  26         --directory|--directory=*)
  27                 # only one is allowed and it should have been handled by tg.sh
  28                 # which means this is the second one and it's a usage error
  29                 usage 1
  30                 ;;
  31         --quote|-q)
  32                 quote=1
  33                 ;;
  34         --)
  35                 shift
  36                 break
  37                 ;;
  38         -?*)
  39                 echo "Unknown option: $1" >&2
  40                 usage 1
  41                 ;;
  42         *)
  43                 break
  44                 ;;
  45 esac; shift; done
  46 [ -n "$wayback" ] || usage 1
  47
  48 # Everything's been handled by tg.sh except for verifying a TTY
  49 # is present for an interactive shell
  50
  51 cmd=
  52 redir=
  53 theshell=@SHELL_PATH@
  54 if [ $# -eq 0 ]; then
  55         [ -z "$SHELL" ] || theshell="$SHELL"
  56         test -t 0 || die "cannot use interactive wayback shell on non-TTY STDIN"
  57         if test -t 1; then
  58                 test -t 2 || redir='2>&1'
  59         elif test -t 2; then
  60                 redir='>&2'
  61         else
  62                 die "cannot use interactive wayback shell on non-TTY STDOUT/STDERR"
  63         fi
  64         PS1='[../${PWD##*/}] wayback$ ' && export PS1
  65         wbname="${wayback#:}"
  66         [ -n "$wbname" ] || wbname='now?!'
  67         eval 'info "going wayback to $wbname..."' "$redir"
  68 else
  69         if [ -z "$quote" ]; then
  70                 cmd='-c "$*"'
  71         else
  72                 # attempt to "quote" the arguments and then glue them together
  73                 cmdstr=
  74                 for cmdword in "$@"; do
  75                         cmdworddq=1
  76                         case "$cmdword" in [A-Za-z_]*)
  77                                 if test z"${cmdword%%[!A-Za-z_0-9]*}" = z"$cmdword"
  78                                 then
  79                                         cmdworddq=
  80                                 else case "$cmdword" in *=*)
  81                                         cmdvar="${cmdword%%=*}"
  82                                         if test z"${cmdvar%%[!A-Za-z_0-9]*}" = z"$cmdvar"
  83                                         then
  84                                                 v_quotearg cmdword "${cmdword#*=}"
  85                                                 cmdword="$cmdvar=$cmdword"
  86                                                 cmdworddq=
  87                                         fi
  88                                 esac; fi
  89                         esac
  90                         test z"$cmdworddq" = z || v_quotearg cmdword "$cmdword"
  91                         cmdstr="${cmdstr:+$cmdstr }$cmdword"
  92                 done
  93                 cmd='-c "$cmdstr"'
  94         fi
  95 fi
  96 eval '"$theshell"' "$cmd" "$redir"