#!/bin/sh

# Display ENAME corresponding to number
# or all ENAMEs if no number specified.

# License: LGPLv2

test $Argc -eq 1 && global re := ""$1([^0-9]|$)""
echo "#include <errno.h>" |
cpp -dD -CC | #-CC available since GCC 3.3 (2003)
grep -E "^#define E[^ ]+ $re" |
sed ':s;s#/\*\([^ ]*\) #/*\1_#;t s;' | column -t | tr _ ' ' | #align
cut -c1-$[tput cols] #truncate to screen width
(CommandList
  children: [
    (AndOr
      children: [
        (C {(Lit_Other "[")} {($ VSub_Pound "$#")} {(-eq)} {(1)} {(Lit_Other "]")})
        (Assignment
          keyword: Assign_None
          pairs: [
            (assign_pair
              lhs: (LhsName name:re)
              op: Equal
              rhs: {(DQ ($ VSub_Number "$1") ("([^0-9]|") (Lit_Other "$") (")"))}
              spids: [27]
            )
          ]
          spids: [27]
        )
      ]
      op_id: Op_DAmp
    )
    (Pipeline
      children: [
        (C {(echo)} {(DQ ("#include <errno.h>"))})
        (C {(cpp)} {(-dD)} {(-CC)})
        (C {(grep)} {(-E)} {(DQ ("^#define E[^ ]+ ") ($ VSub_Name "$re"))})
        (C {(sed)} {(SQ <":s;s#/\\*\\([^ ]*\\) #/*\\1_#;t s;">)})
        (C {(column)} {(-t)})
        (C {(tr)} {(_)} {(SQ <" ">)})
        (C {(cut)} 
          {(-c1-) 
            (CommandSubPart
              command_list: (CommandList children:[(C {(tput)} {(cols)})])
              left_token: <Left_CommandSub "$(">
              spids: [95 99]
            )
          }
        )
      ]
      negated: False
    )
  ]
)