fltk/src/filename_expand.cxx

126 lines
3.5 KiB
C++

//
// "$Id$"
//
// Filename expansion routines for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
/* expand a file name by substuting environment variables and
home directories. Returns true if any changes were made.
to & from may be the same buffer.
*/
#include <FL/filename.H>
#include <FL/fl_utf8.h>
#include <stdlib.h>
#include "flstring.h"
#if defined(WIN32) && !defined(__CYGWIN__)
#include <windows.h>
#else
# include <unistd.h>
# include <pwd.h>
#endif
#if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
static inline int isdirsep(char c) {return c=='/' || c=='\\';}
#else
#define isdirsep(c) ((c)=='/')
#endif
/** Expands a filename containing shell variables and tilde (~).
Currently handles these variants:
\code
"~username" // if 'username' does not exist, result will be unchanged
"~/file"
"$VARNAME" // does NOT handle ${VARNAME}
\endcode
\b Examples:
\code
#include <FL/filename.H>
[..]
putenv("TMPDIR=/var/tmp");
fl_filename_expand(out, sizeof(out), "~fred/.cshrc"); // out="/usr/fred/.cshrc"
fl_filename_expand(out, sizeof(out), "~/.cshrc"); // out="/usr/<yourname>/.cshrc"
fl_filename_expand(out, sizeof(out), "$TMPDIR/foo.txt"); // out="/var/tmp/foo.txt"
\endcode
\param[out] to resulting expanded filename
\param[in] tolen size of the expanded filename buffer
\param[in] from filename containing shell variables
\return 0 if no change, non zero otherwise
*/
int fl_filename_expand(char *to,int tolen, const char *from) {
char *temp = new char[tolen];
strlcpy(temp,from, tolen);
char *start = temp;
char *end = temp+strlen(temp);
int ret = 0;
for (char *a=temp; a<end; ) { // for each slash component
char *e; for (e=a; e<end && !isdirsep(*e); e++); // find next slash
const char *value = 0; // this will point at substitute value
switch (*a) {
case '~': // a home directory name
if (e <= a+1) { // current user's directory
value = fl_getenv("HOME");
#ifndef WIN32
} else { // another user's directory
struct passwd *pwd;
char t = *e; *(char *)e = 0;
pwd = getpwnam(a+1);
*(char *)e = t;
if (pwd) value = pwd->pw_dir;
#endif
}
break;
case '$': /* an environment variable */
{char t = *e; *(char *)e = 0; value = fl_getenv(a+1); *(char *)e = t;}
break;
}
if (value) {
// substitutions that start with slash delete everything before them:
if (isdirsep(value[0])) start = a;
#if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
// also if it starts with "A:"
if (value[0] && value[1]==':') start = a;
#endif
int t = (int) strlen(value); if (isdirsep(value[t-1])) t--;
if ((end+1-e+t) >= tolen) end += tolen - (end+1-e+t);
memmove(a+t, e, end+1-e);
end = a+t+(end-e);
*end = '\0';
memcpy(a, value, t);
ret++;
} else {
a = e+1;
#if defined(WIN32) || defined(__EMX__) && !defined(__CYGWIN__)
if (*e == '\\') {*e = '/'; ret++;} // ha ha!
#endif
}
}
strlcpy(to, start, tolen);
delete[] temp;
return ret;
}
//
// End of "$Id$".
//