components/libtecla/files/ef_expand_file.3tecla
changeset 681 7c568e880861
child 5810 76203f2cf39d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/libtecla/files/ef_expand_file.3tecla	Wed Feb 08 16:47:41 2012 -0800
@@ -0,0 +1,194 @@
+'\" te
+.\" Copyright (c) 2000, 2001, 2002, 2003, 2004 by Martin C. Shepherd. All Rights Reserved.
+.\" Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, provided that the above copyright notice(s) and this permission notice appear in all copies of the Software and that both the above copyright notice(s) and this permission notice appear in supporting documentation.  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  Except as contained in this notice, the name of a copyright holder shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization of the copyright holder.
+.\" Portions Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
+.TH ef_expand_file 3TECLA "13 May 2011" "SunOS 5.11" "Interactive Command-line Input Library Functions"
+.SH NAME
+ef_expand_file, del_ExpandFile, ef_last_error, ef_list_expansions, new_ExpandFile \- expand filename and wildcard expressions
+.SH SYNOPSIS
+.LP
+.nf
+cc [ \fIflag\fR\&.\|.\|. ] \fIfile\fR\&.\|.\|. \fB-ltecla\fR [ \fIlibrary\fR\&.\|.\|. ] 
+#include <libtecla.h>
+
+\fBExpandFile *\fR\fBef_expand_file\fR(\fBvoid\fR);
+.fi
+
+.LP
+.nf
+\fBExpandFile *\fR\fBdel_ExpandFile\fR(\fBExpandFile *\fR\fIef\fR);
+.fi
+
+.LP
+.nf
+\fBFileExpansion *\fR\fBef_last_error\fR(\fBExpandFile *\fR\fIef\fR, \fBconst char *\fR\fIpath\fR,
+     \fBint\fR \fIpathlen\fR);
+.fi
+
+.LP
+.nf
+\fBint\fR \fBef_list_expansions\fR(\fBFileExpansion *\fR\fIresult\fR, \fBFILE *\fR\fIfp\fR, \fBint\fR \fIterm_width\fR);
+.fi
+
+.LP
+.nf
+\fBconst char *\fR\fBnew_ExpandFile\fR(\fBExpandFile *\fR\fIef\fR);
+.fi
+
+.SH DESCRIPTION
+.sp
+.LP
+The \fBef_expand_file()\fR function is part of the \fBlibtecla\fR(3LIB) library. It expands a specified filename, converting ~user/ and ~/ expressions at the start of the filename to the corresponding home directories, replacing $\fBenvvar\fR 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 backslashes that are themselves preceded by backslashes are preserved in the expanded filename.
+.sp
+.LP
+In the presence of wildcards, the returned list of filenames includes only 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 \fBtcsh\fR shell.
+.sp
+.LP
+The supported wildcards and their meanings are:
+.sp
+.ne 2
+.mk
+.na
+\fB\fB*\fR\fR
+.ad
+.RS 12n
+.rt  
+Match any sequence of zero or more characters.
+.RE
+
+.sp
+.ne 2
+.mk
+.na
+\fB\fB?\fR\fR
+.ad
+.RS 12n
+.rt  
+Match any single character.
+.RE
+
+.sp
+.ne 2
+.mk
+.na
+\fB[\fB\fIchars\fR\fR]\fR
+.ad
+.RS 12n
+.rt  
+Match any single character that appears in \fIchars\fR. If \fIchars\fR contains an expression of the form a-b, then any character between a and b, including a and b, matches. The '-' character loses its special meaning as a range specifier when it appears at the start of the sequence of characters. The ']' character also loses 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.
+.RE
+
+.sp
+.ne 2
+.mk
+.na
+\fB[^\fIchars\fR]\fR
+.ad
+.RS 12n
+.rt  
+The same as [\fIchars\fR] except that it matches any single character that does not appear in \fIchars\fR.
+.RE
+
+.sp
+.LP
+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 \fBls\fR(1) command.
+.sp
+.LP
+The \fBnew_ExpandFile()\fR function creates the resources used by the \fBef_expand_file()\fR function. In particular, it maintains the memory that is used to record the array of matching file names that is returned by \fBef_expand_file()\fR. This array is expanded as needed, so there is no builtin limit to the number of files that can be matched.
+.sp
+.LP
+The \fBdel_ExpandFile()\fR function deletes the resources that were returned by a previous call to \fBnew_ExpandFile()\fR. It always returns NULL (that is, a deleted object). It does nothing if the \fIef\fR argument is NULL.
+.sp
+.LP
+The \fBef_expand_file()\fR function performs filename expansion. Its first argument is a resource object returned by \fBnew_ExpandFile()\fR. A pointer to the start of the filename to be matched is passed by the \fIpath\fR argument. This must be a normal null-terminated string, but unless a length of -1 is passed in \fIpathlen\fR, only the first \fIpathlen\fR characters will be used in the filename expansion. If the length is specified as -1, the whole of the string will be expanded. A container of the following type is returned by \fBef_expand_file()\fR.
+.sp
+.in +2
+.nf
+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;
+.fi
+.in -2
+
+.sp
+.LP
+The \fBef_expand_file()\fR function returns a pointer to a container whose contents are the results of the expansion. If there were no wildcards in the filename, the \fInfile\fR member will be 1, and the \fIexists\fR member should be queried if it is important to know if the expanded file currently exists. If there were wild cards, then the contained \fIfiles\fR[] array will contain the names of the \fInfile\fR existing files that matched the wild-carded filename, and the \fIexists\fR 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 \fBef_expand_file()\fR, you should either make a private copy of the returned results, or create multiple file-expansion resource objects with multiple calls to \fBnew_ExpandFile()\fR.
+.sp
+.LP
+On error, \fINULL\fR is returned, and an explanation of the error can be determined by calling \fBef_last_error\fR(\fIef\fR).
+.sp
+.LP
+The \fBef_last_error()\fR function returns the message which describes the error that occurred on the last call to \fBef_expand_file()\fR, for the given (\fBExpandFile *\fR\fIef\fR) resource object.
+.sp
+.LP
+The \fBef_list_expansions()\fR function provides a convenient way to list the filename expansions returned by \fBef_expand_file()\fR. Like the \fBls\fR utility, 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 \fBstdio\fR stream specified by the \fIfp\fR argument.
+.SS "Thread Safety"
+.sp
+.LP
+It is safe to use the facilities of this module in multiple threads, provided that each thread uses a separately allocated \fBExpandFile\fR object. In other words, if two threads want to do file expansion, they should each call \fBnew_ExpandFile()\fR to allocate their own file-expansion objects.
+.SH EXAMPLES
+.LP
+\fBExample 1 \fRUse of file expansion function.
+.sp
+.LP
+The following is a complete example of how to use the file expansion function.
+
+.sp
+.in +2
+.nf
+#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).\en", arg,
+              ef_last_error(ef));
+       } else {
+          printf("%s matches the following files:\en", arg);
+          for(i=0; i<expn->nfile; i++)
+              printf(" %s\en", expn->files[i]);
+       }
+    }
+ 
+    ef = del_ExpandFile(ef);
+    return 0;
+}
+.fi
+.in -2
+
+.SH ATTRIBUTES
+.sp
+.LP
+See \fBattributes\fR(5) for descriptions of the following attributes:
+.sp
+
+.sp
+.TS
+tab() box;
+cw(2.75i) |cw(2.75i) 
+lw(2.75i) |lw(2.75i) 
+.
+ATTRIBUTE TYPEATTRIBUTE VALUE
+_
+Interface StabilityCommitted
+_
+MT-LevelMT-Safe
+.TE
+
+.SH SEE ALSO
+.sp
+.LP
+\fBcpl_complete_word\fR(3TECLA), \fBgl_get_line\fR(3TECLA), \fBlibtecla\fR(3LIB), \fBpca_lookup_file\fR(3TECLA), \fBattributes\fR(5)