Is there an equivalent for Glob in D Phobos? - d

Question

In python I can use glob to search path patterns. This for instance:
import glob
for entry in glob.glob("/usr/*/python*"):
print(entry)
Would print this:
/usr/share/python3
/usr/share/python3-plainbox
/usr/share/python
/usr/share/python-apt
/usr/include/python3.5m
/usr/bin/python3
/usr/bin/python3m
/usr/bin/python2.7
/usr/bin/python
/usr/bin/python3.5
/usr/bin/python3.5m
/usr/bin/python2
/usr/lib/python3
/usr/lib/python2.7
/usr/lib/python3.5
How would I glob or make a glob equivalent in in D?
------Updated on Sep 12 2017------
I wrote a small D module to do Glob in D: https://github.com/workhorsy/d-glob

Answer 1

If you only work on a Posix system, you can directly call glob.h. Here's a simple example that shows how easy it is to interface with the Posix API:
void main()
{
import std.stdio;
import glob : glob;
foreach(entry; glob("/usr/*/python*"))
writeln(entry);
}
You can compile this e.g. with rdmd main.d (rdmd does simple dependency management) or dmd main.d glob.d and it yields a similar output as yours on my machine.
glob.d was generated by dstep and is enhanced with a convenience D-style wrapper (first function). Please note that this isn't perfect and a better way would be to expose a range API instead of allocating the entire array.
/* Copyright (C) 1991-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
string[] glob(string pattern)
{
import std.string;
string[] results;
glob_t glob_result;
glob(pattern.toStringz, 0, null, &glob_result);
for (uint i = 0; i < glob_result.gl_pathc; i++)
{
results ~= glob_result.gl_pathv[i].fromStringz().idup;
}
globfree(&glob_result);
return results;
}
import core.stdc.config;
extern (C):
enum _GLOB_H = 1;
/* We need `size_t' for the following definitions. */
alias c_ulong __size_t;
alias c_ulong size_t;
/* The GNU CC stddef.h version defines __size_t as empty. We need a real
definition. */
/* Bits set in the FLAGS argument to `glob'. */
enum GLOB_ERR = 1 << 0; /* Return on read errors. */
enum GLOB_MARK = 1 << 1; /* Append a slash to each name. */
enum GLOB_NOSORT = 1 << 2; /* Don't sort the names. */
enum GLOB_DOOFFS = 1 << 3; /* Insert PGLOB->gl_offs NULLs. */
enum GLOB_NOCHECK = 1 << 4; /* If nothing matches, return the pattern. */
enum GLOB_APPEND = 1 << 5; /* Append to results of a previous call. */
enum GLOB_NOESCAPE = 1 << 6; /* Backslashes don't quote metacharacters. */
enum GLOB_PERIOD = 1 << 7; /* Leading `.' can be matched by metachars. */
enum GLOB_MAGCHAR = 1 << 8; /* Set in gl_flags if any metachars seen. */
enum GLOB_ALTDIRFUNC = 1 << 9; /* Use gl_opendir et al functions. */
enum GLOB_BRACE = 1 << 10; /* Expand "{a,b}" to "a" "b". */
enum GLOB_NOMAGIC = 1 << 11; /* If no magic chars, return the pattern. */
enum GLOB_TILDE = 1 << 12; /* Expand ~user and ~ to home directories. */
enum GLOB_ONLYDIR = 1 << 13; /* Match only directories. */
enum GLOB_TILDE_CHECK = 1 << 14; /* Like GLOB_TILDE but return an error
if the user name is not available. */
enum __GLOB_FLAGS = GLOB_ERR | GLOB_MARK | GLOB_NOSORT | GLOB_DOOFFS | GLOB_NOESCAPE | GLOB_NOCHECK | GLOB_APPEND | GLOB_PERIOD | GLOB_ALTDIRFUNC | GLOB_BRACE | GLOB_NOMAGIC | GLOB_TILDE | GLOB_ONLYDIR | GLOB_TILDE_CHECK;
/* Error returns from `glob'. */
enum GLOB_NOSPACE = 1; /* Ran out of memory. */
enum GLOB_ABORTED = 2; /* Read error. */
enum GLOB_NOMATCH = 3; /* No matches found. */
enum GLOB_NOSYS = 4; /* Not implemented. */
/* Previous versions of this file defined GLOB_ABEND instead of
GLOB_ABORTED. Provide a compatibility definition here. */
/* Structure describing a globbing run. */
struct glob_t
{
__size_t gl_pathc; /* Count of paths matched by the pattern. */
char** gl_pathv; /* List of matched pathnames. */
__size_t gl_offs; /* Slots to reserve in `gl_pathv'. */
int gl_flags; /* Set to FLAGS, maybe | GLOB_MAGCHAR. */
/* If the GLOB_ALTDIRFUNC flag is set, the following functions
are used instead of the normal file access functions. */
void function (void*) gl_closedir;
void* function (void*) gl_readdir;
void* function (const(char)*) gl_opendir;
int function (const(char)*, void*) gl_lstat;
int function (const(char)*, void*) gl_stat;
}
/* If the GLOB_ALTDIRFUNC flag is set, the following functions
are used instead of the normal file access functions. */
/* Do glob searching for PATTERN, placing results in PGLOB.
The bits defined above may be set in FLAGS.
If a directory cannot be opened or read and ERRFUNC is not nil,
it is called with the pathname that caused the error, and the
`errno' value from the failing call; if it returns non-zero
`glob' returns GLOB_ABEND; if it returns zero, the error is ignored.
If memory cannot be allocated for PGLOB, GLOB_NOSPACE is returned.
Otherwise, `glob' returns zero. */
int glob (
const(char)* __pattern,
int __flags,
int function (const(char)*, int) __errfunc,
glob_t* __pglob);
/* Free storage allocated in PGLOB by a previous `glob' call. */
void globfree (glob_t* __pglob);

Answer 2

None of the answers above worked 100% the same as Glob on Windows and Linux. So I made a small D module that does Glob the right way. Hopefully people find it useful:
https://github.com/workhorsy/d-glob
import std.stdio : stdout;
import glob : glob;
foreach (entry ; glob("/usr/*/python*")) {
stdout.writefln("%s", entry);
}

Answer 3

Maybe you are looking for std.file.dirEntries().
Here's example from the documentation:
// Iterate over all D source files in current directory and all its
// subdirectories
auto dFiles = dirEntries("","*.{d,di}",SpanMode.depth);
foreach(d; dFiles)
writeln(d.name);

Answer 4

Basically you don't need to do all this complicated stuff with headers, C and so on, and so forth. This should do the thing:
auto dirIter = dirEntries("/usr", "*/python*", SpanMode.shallow);
foreach(dirFile; dirIter) {
// Process the result as needed