SH-SEXPRS(1)                                         SH-SEXPRS(1)

     NAME
          sexprs, islist, els, text, textels, mktext, mklist,
          mktextlist - parse and generate S-expressions

     SYNOPSIS
          load sexprs

          getsexprs command
          islist sexpr
          ${els sexpr}
          ${text sexpr}
          ${textels sexpr}
          ${mktext val}
          ${mklist [ val...
          ${mktextlist [ val...

     DESCRIPTION
          Sexprs is a loadable module for sh(1) that provides the
          facility to parse and generate S-expressions (see
          sexprs(2)). The following primitives are provided:

          getsexprs Getsexprs works similiarly to getlines in sh-std(1). It reads S-expressions from the standard
                    input, and for expression read, it invokes command
                    with $sexp set to the text representation of that
                    expression.  Getsexprs recognises the usual loop
                    break and continue exceptions.

          islist sexp
                    Islist yields a nil (true) status if sexp, which
                    must be a well-formed S-expression, is a list ele-
                    ment.

          ${els sexp}
                    If sexp is an S-expression containing a list, then
                    els returns a list of the S-expressions it con-
                    tains.  It is an error if sexp is not a valid S-
                    expression.

          ${text sexp}
                    If sexp is an S-expression containing a simple
                    element, then text returns the value of that ele-
                    ment. If sexp is a list, the return value will be
                    an empty string.  Note that elements containing
                    binary data will likely be corrupted by conversion
                    to utf-8.  It is an error if sexp is not a valid
                    S-expression.

          ${textels sexp}
                    If sexp is an S-expression containing a list, then

     SH-SEXPRS(1)                                         SH-SEXPRS(1)

                    textels returns a list of the text values in that
                    S-expression, converted as with ${text}.  It is an
                    error if sexp is not a valid S-expression.

          ${mktext val}
                    Mktext returns a text representation of the S-
                    expression containing the simple value val.

          ${mklist [sexp...]}
                    Mklist returns a text representation of the S-
                    expression list containing its arguments, which
                    must be well-format S-expressions.

          ${mktextlist [val...]}
                    Mktextlist returns a text representation of the
                    S-expression list containing one simple element
                    for each val.

     SOURCE
          /appl/cmd/sh/sexprs.b

     SEE ALSO
          sh(1), sh-std(1), sexprs(2)