gen/wordexp.3

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  26 .\" $FreeBSD: src/lib/libc/gen/wordexp.3,v 1.6 2003/09/08 19:57:14 ru Exp $
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  28 .Dd December 27, 2002
  29 .Dt WORDEXP 3
  30 .Os
  31 .Sh NAME
  32 .Nm wordexp
  33 .Nd "perform shell-style word expansions"
  34 .Sh SYNOPSIS
  35 .In wordexp.h
  36 .Ft int
  37 .Fo wordexp
  38 .Fa "const char *restrict words"
  39 .Fa "wordexp_t *restrict pwordexp"
  40 .Fa "int flags"
  41 .Fc
  42 .Ft void
  43 .Fo wordfree
  44 .Fa "wordexp_t *pwordexp"
  45 .Fc
  46 .Sh DESCRIPTION
  47 The
  48 .Fn wordexp
  49 function performs shell-style word expansion on
  50 .Fa words .
  51 It places the list of words into the
  52 .Va we_wordv
  53 member of
  54 .Fa pwordexp
  55 and the number of words into
  56 .Va we_wordc .
  57 .Pp
  58 The
  59 .Fa flags
  60 argument (see
  61 .Sx BUGS )
  62 is the bitwise inclusive OR of any of the following constants:
  63 .Bl -tag -width ".Dv WRDE_SHOWERR"
  64 .It Dv WRDE_APPEND
  65 Append the words to those generated by a previous call to
  66 .Fn wordexp .
  67 .It Dv WRDE_DOOFS
  68 As many
  69 .Dv NULL
  70 pointers as are specified by the
  71 .Va we_offs
  72 member of
  73 .Fa pwordexp
  74 are added to the front of
  75 .Va we_wordv .
  76 .It Dv WRDE_NOCMD
  77 Disallow command substitution in
  78 .Fa words .
  79 See the note in
  80 .Sx BUGS
  81 before using this.
  82 .It Dv WRDE_REUSE
  83 The
  84 .Fa pwordexp
  85 argument was passed to a previous successful call to
  86 .Fn wordexp
  87 but has not been passed to
  88 .Fn wordfree .
  89 The implementation may reuse the space allocated to it.
  90 .It Dv WRDE_SHOWERR
  91 Do not redirect shell error messages to
  92 .Pa /dev/null .
  93 .It Dv WRDE_UNDEF
  94 Report error on an attempt to expand an undefined shell variable.
  95 .El
  96 .Pp
  97 The
  98 .Vt wordexp_t
  99 structure is defined in
 100 .In wordexp.h
 101 as:
 102 .Bd -literal -offset indent
 103 typedef struct {
 104         size_t  we_wordc;       /* count of words matched */
 105         char    **we_wordv;     /* pointer to list of words */
 106         size_t  we_offs;        /* slots to reserve in we_wordv */
 107 } wordexp_t;
 108 .Ed
 109 .Pp
 110 The
 111 .Fn wordfree
 112 function frees the memory allocated by
 113 .Fn wordexp .
 114 .Sh RETURN VALUES
 115 The
 116 .Fn wordexp
 117 function returns zero if successful, otherwise it returns one of the following
 118 error codes:
 119 .Bl -tag -width ".Dv WRDE_NOSPACE"
 120 .It Dv WRDE_BADCHAR
 121 The
 122 .Fa words
 123 argument contains one of the following unquoted characters:
 124 .Aq newline ,
 125 .Ql | ,
 126 .Ql & ,
 127 .Ql \&; ,
 128 .Ql < ,
 129 .Ql > ,
 130 .Ql \&( ,
 131 .Ql \&) ,
 132 .Ql { ,
 133 .Ql } .
 134 .It Dv WRDE_BADVAL
 135 An attempt was made to expand an undefined shell variable and
 136 .Dv WRDE_UNDEF
 137 is set in
 138 .Fa flags .
 139 .It Dv WRDE_CMDSUB
 140 An attempt was made to use command substitution and
 141 .Dv WRDE_NOCMD
 142 is set in
 143 .Fa flags .
 144 .It Dv WRDE_NOSPACE
 145 Not enough memory to store the result.
 146 .It Dv WRDE_SYNTAX
 147 Shell syntax error in
 148 .Fa words .
 149 .El
 150 .Pp
 151 The
 152 .Fn wordfree
 153 function returns no value.
 154 .Sh EXAMPLES
 155 Invoke the editor on all
 156 .Pa .c
 157 files in the current directory
 158 and
 159 .Pa /etc/motd
 160 (error checking omitted):
 161 .Bd -literal -offset indent
 162 wordexp_t pwordexp;
 163
 164 wordexp("${EDITOR:-vi} *.c /etc/motd", &pwordexp, 0);
 165 execvp(pwordexp->we_wordv[0], pwordexp->we_wordv);
 166 .Ed
 167 .Sh SEE ALSO
 168 .Xr sh 1 ,
 169 .Xr fnmatch 3 ,
 170 .Xr glob 3 ,
 171 .Xr popen 3 ,
 172 .Xr system 3
 173 .Sh BUGS
 174 This version of
 175 .Fn wordexp
 176 ignores the value of the
 177 .Fa flags
 178 argument.
 179 .Sh COPYRIGHT
 180 Copyright 1995-2002 University Corporation for Atmospheric Research/Unidata
 181 .Pp
 182 Portions of this software were developed by the Unidata Program at the
 183 University Corporation for Atmospheric Research.