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@darealshinji
Last active Jan 10, 2021
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wslpath wrapper
/**
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* 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.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* For more information, please refer to <http://unlicense.org/>
*/
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
// this is a wrapper around the wslpath command
//
// path - input path
// buf - buffer to store translated path
// szBuf - size of buffer
//
// mode:
// "-u" or "u" - Windows path to Unix path
// "-w" or "w" - Unix path to Windows path
// "-m" or "m" - Unix path to Windows path, using '/' as path separator
// any other arguments (including NULL) will be treated like "-u"
//
// absolute - set non-zero to force result to absolute path format
//
char *wslpath(const char *path, char *buf, size_t szBuf, const char *mode, int absolute);
FILE *popen_wslpath(const char *mode, const char *path, int readErr, int absolute)
{
enum { r = 0, w = 1 };
int fd[2];
int fdnull;
pid_t pid;
char *argv[5] = { "wslpath", NULL, NULL, NULL, NULL };
if (pipe2(fd, O_CLOEXEC) == -1) {
//perror("pipe2()");
return NULL;
}
if ((pid = fork()) == -1) {
//perror("fork()");
return NULL;
}
if (pid != 0) {
// parent process reads from pipe
close(fd[w]);
return fdopen(fd[r], "r");
}
// child process writes to pipe
fdnull = open("/dev/null", O_WRONLY|O_CLOEXEC);
if (readErr == 0) {
dup2(fd[w], STDOUT_FILENO); // read stdout
dup2(fdnull, STDERR_FILENO); // silence stderr
} else {
dup2(fd[w], STDERR_FILENO); // read stderr
dup2(fdnull, STDOUT_FILENO); // silence stdout
}
close(fd[r]);
close(fd[w]);
if (absolute == 0) {
argv[1] = (char * const) mode;
argv[2] = (char * const) path;
} else {
argv[1] = "-a"; // does this even have any effect on the output at all?
argv[2] = (char * const) mode;
argv[3] = (char * const) path;
}
execvp("wslpath", argv);
_exit(127);
return NULL;
}
char *wslpath(const char *path, char *buf, size_t szBuf, const char *mode, int absolute)
{
FILE *fp;
size_t len;
int errsv = 0;
const char *arg = "-u";
if (!path || strlen(path) == 0 || !buf || szBuf < 1) {
errno = EINVAL; // Invalid argument
return NULL;
}
if (mode) {
if (strcasecmp(mode, "w") == 0 || strcasecmp(mode, "-w") == 0) {
arg = "-w";
} else if (strcasecmp(mode, "m") == 0 || strcasecmp(mode, "-m") == 0) {
arg = "-m";
}
}
// unfortunately wslpath always returns 0 and prints help to stdout on error;
// to figure out if an error occured, redirect stdout to /dev/null
// and read from stderr; if nothing was read, then no error occurred and
// we can do the same again, now reading the result from stdin
// check stderr
if ((fp = popen_wslpath(arg, path, 1, absolute)) == NULL) {
return NULL;
}
if (fread(buf, 1, szBuf, fp) > 0 || !feof(fp) || ferror(fp)) {
// wslpath returned a message to stderr
pclose(fp);
errno = ECANCELED; // Operation canceled
return NULL;
}
// now read from stdin
if ((fp = popen_wslpath(arg, path, 0, absolute)) == NULL) {
return NULL;
}
if ((len = fread(buf, 1, szBuf, fp)) > 0 && feof(fp) && !ferror(fp)) {
// remove trailing newline
buf[len - 1] = 0;
} else {
errsv = (errno == 0) ? -1 : errno;
buf = NULL;
}
pclose(fp);
errno = errsv;
return buf;
}
int main()
{
const char *input = "\\\\wsl$\\Ubuntu\\usr\\bin\\..";
char buf[2048];
if (wslpath(input, buf, sizeof(buf) - 1, "u", 1)) {
printf("input: %s\n", input);
printf("result: %s\n", buf);
} else {
perror("wslpath()");
return 1;
}
return 0;
}
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