Provided by: libtecla1-dev_1.6.1-5_i386 bug

NAME

       ef_expand_file,   del_ExpandFile,   ef_last_error,  ef_list_expansions,
       new_ExpandFile - expand filenames containing ~user/$envvar and wildcard
       expressions

SYNOPSIS

       #include <libtecla.h>

       ExpandFile *new_ExpandFile(void);

       ExpandFile *del_ExpandFile(ExpandFile *ef);

       FileExpansion *ef_expand_file(ExpandFile *ef,
                                     const char *path,
                                     int pathlen);

       int ef_list_expansions(FileExpansion *result, FILE *fp,
                              int term_width);

       const char *ef_last_error(ExpandFile *ef);

DESCRIPTION

       The  ef_expand_file()  function  is  part of the tecla library (see the
       libtecla(3) man page). It  expands  a  specified  filename,  converting
       ~user/  and  ~/  expressions  at  the  start  of  the  filename  to the
       corresponding home directories, replacing $envvar with the value of the
       corresponding   environment  variable,  and  then,  if  there  are  any
       wildcards, matching these against existing  filenames.  Backslashes  in
       the  input filename are interpreted as escaping any special meanings of
       the characters that follow them.  Only backslahes that  are  themselves
       preceded by backslashes are preserved in the expanded filename.

       In  the  presence  of  wildcards,  the  returned list of filenames only
       includes the  names  of  existing  files  which  match  the  wildcards.
       Otherwise,  the  original filename is returned after expansion of tilde
       and dollar expressions, and the result is not checked against  existing
       files. This mimics the file-globbing behavior of the unix tcsh shell.

       The supported wildcards and their meanings are:
         *        -  Match any sequence of zero or more characters.
         ?        -  Match any single character.
         [chars]  -  Match any single character that appears in
                     'chars'.  If 'chars' contains an expression of
                     the form a-b, then any character between a and
                     b, including a and b, matches. The '-'
                     character looses its special meaning as a
                     range specifier when it appears at the start
                     of the sequence of characters. The ']'
                     character also looses its significance as the
                     terminator of the range expression if it
                     appears immediately after the opening '[', at
                     which point it is treated one of the
                     characters of the range. If you want both '-'
                     and ']' to be part of the range, the '-'
                     should come first and the ']' second.

         [^chars] -  The same as [chars] except that it matches any
                     single character that doesn't appear in
                     'chars'.

       Note that wildcards never match the initial dot in filenames that start
       with '.'. The initial '.' must be explicitly specified in the filename.
       This  again  mimics  the globbing behavior of most unix shells, and its
       rational is based in the fact that in unix, files with names that start
       with  '.'  are usually hidden configuration files, which are not listed
       by default by the ls command.

       The following is a complete example of how to use  the  file  expansion
       function.

         #include <stdio.h>
         #include <libtecla.h>

         int main(int argc, char *argv[])
         {
           ExpandFile *ef;      /* The expansion resource object */
           char *filename;      /* The filename being expanded */
           FileExpansion *expn; /* The results of the expansion */
           int i;

           ef = new_ExpandFile();
           if(!ef)
             return 1;

           for(arg = *(argv++); arg; arg = *(argv++)) {
             if((expn = ef_expand_file(ef, arg, -1)) == NULL) {
               fprintf(stderr, "Error expanding %s (%s).\n", arg,
                                ef_last_error(ef));
             } else {
               printf("%s matches the following files:\n", arg);
               for(i=0; i<expn->nfile; i++)
                 printf(" %s\n", expn->files[i]);
             }
           }

           ef = del_ExpandFile(ef);
           return 0;
         }

       Descriptions of the functions used above are as follows:

         ExpandFile *new_ExpandFile(void)

       This  function  creates  the  resources  used  by  the ef_expand_file()
       function. In particular, it maintains the memory that is used to record
       the  array  of matching filenames that is returned by ef_expand_file().
       This array is expanded as needed, so there is no built in limit to  the
       number of files that can be matched.

         ExpandFile *del_ExpandFile(ExpandFile *ef)

       This  function  deletes  the resources that were returned by a previous
       call to new_ExpandFile(). It always returns NULL (ie a deleted object).
       It does nothing if the ef argument is NULL.

       A container of the following type is returned by ef_expand_file().

         typedef struct {
           int exists;   /* True if the files in files[] exist */
           int nfile;    /* The number of files in files[] */
           char **files; /* An array of 'nfile' filenames. */
         } FileExpansion;

         FileExpansion *ef_expand_file(ExpandFile *ef,
                                       const char *path,
                                       int pathlen)

       The   ef_expand_file()   function   performs   filename  expansion,  as
       documented at the start of  this  section.  Its  first  argument  is  a
       resource object returned by new_ExpandFile(). A pointer to the start of
       the filename to be matched is passed via the path argument.  This  must
       be  a normal NUL terminated string, but unless a length of -1 is passed
       in pathlen, only the first pathlen  characters  will  be  used  in  the
       filename expansion.  If the length is specified as -1, the whole of the
       string will be expanded.

       The function returns a pointer to a container who's  contents  are  the
       results  of  the expansion. If there were no wildcards in the filename,
       the nfile member will be 1, and the exists member should be queried  if
       it  is  important to know if the expanded file currently exists or not.
       If there were wildcards, then the contained files[] array will  contain
       the  names  of  the  nfile  existing  files that matched the wildcarded
       filename, and the exists member will have the value 1.  Note  that  the
       returned container belongs to the specified ef object, and its contents
       will change on each call, so if you need to retain the results of  more
       than  one  call  to  ef_expand_file(), you should either make a private
       copy  of  the  returned  results,  or  create  multiple  file-expansion
       resource objects via multiple calls to new_ExpandFile().

       On  error,  NULL  is  returned,  and an explanation of the error can be
       determined by calling ef_last_error(ef).

         const char *ef_last_error(ExpandFile *ef)

       This function returns  the  message  which  describes  the  error  that
       occurred   on   the  last  call  to  ef_expand_file(),  for  the  given
       (ExpandFile *ef) resource object.

         int ef_list_expansions(FileExpansion *result, FILE *fp,
                                int terminal_width);

       The ef_list_expansions() function provides a convenient way to list the
       filename  expansions  returned  by  ef_expand_file().  Like the unix ls
       command, it arranges the  filenames  into  equal  width  columns,  each
       column having the width of the largest file. The number of columns used
       is thus determined by the length  of  the  longest  filename,  and  the
       specified  terminal  width.  Beware that filenames that are longer than
       the specified terminal width are printed without  being  truncated,  so
       output  longer than the specified terminal width can occur. The list is
       written to the stdio stream specified by the fp argument.

THREAD SAFETY

       In multi-threaded programs, you should use the libtecla_r.a version  of
       the library. This uses POSIX reentrant functions where available (hence
       the _r suffix), and disables features that rely on non-reentrant system
       functions. Currently there are no features disabled in this module.

       Using  the  libtecla_r.a  version of the library, it is safe to use the
       facilities of this module  in  multiple  threads,  provided  that  each
       thread  uses  a separately allocated ExpandFile object. In other words,
       if two threads want  to  do  file  expansion,  they  should  each  call
       new_ExpandFile() to allocate their own file-expansion objects.

FILES

       libtecla.a    -    The tecla library
       libtecla.h    -    The tecla header file.

SEE ALSO

       libtecla(3), gl_get_line(3), cpl_complete_word(3),
       pca_lookup_file(3)

AUTHOR

       Martin Shepherd  (mcs@astro.caltech.edu)

                                                             ef_expand_file(3)