fish-shell/path.cpp
2013-10-01 08:25:13 +02:00

488 lines
12 KiB
C++

#include "config.h"
#include <stdlib.h>
#include <stdio.h>
#include <wchar.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <libgen.h>
#include "fallback.h"
#include "util.h"
#include "common.h"
#include "env.h"
#include "wutil.h"
#include "path.h"
#include "expand.h"
/**
Unexpected error in path_get_path()
*/
#define MISSING_COMMAND_ERR_MSG _( L"Error while searching for command '%ls'" )
static bool path_get_path_core(const wcstring &cmd, wcstring *out_path, const env_var_t &bin_path_var)
{
int err = ENOENT;
debug(3, L"path_get_path( '%ls' )", cmd.c_str());
/* If the command has a slash, it must be a full path */
if (cmd.find(L'/') != wcstring::npos)
{
if (waccess(cmd, X_OK)==0)
{
struct stat buff;
if (wstat(cmd, &buff))
{
return false;
}
if (S_ISREG(buff.st_mode))
{
if (out_path)
out_path->assign(cmd);
return true;
}
else
{
errno = EACCES;
return false;
}
}
else
{
struct stat buff;
wstat(cmd, &buff);
return false;
}
}
else
{
wcstring bin_path;
if (! bin_path_var.missing())
{
bin_path = bin_path_var;
}
else
{
if (contains(PREFIX L"/bin", L"/bin", L"/usr/bin"))
{
bin_path = L"/bin" ARRAY_SEP_STR L"/usr/bin";
}
else
{
bin_path = L"/bin" ARRAY_SEP_STR L"/usr/bin" ARRAY_SEP_STR PREFIX L"/bin";
}
}
wcstring nxt_path;
wcstokenizer tokenizer(bin_path, ARRAY_SEP_STR);
while (tokenizer.next(nxt_path))
{
if (nxt_path.empty())
continue;
append_path_component(nxt_path, cmd);
if (waccess(nxt_path, X_OK)==0)
{
struct stat buff;
if (wstat(nxt_path, &buff)==-1)
{
if (errno != EACCES)
{
wperror(L"stat");
}
continue;
}
if (S_ISREG(buff.st_mode))
{
if (out_path)
out_path->swap(nxt_path);
return true;
}
err = EACCES;
}
else
{
switch (errno)
{
case ENOENT:
case ENAMETOOLONG:
case EACCES:
case ENOTDIR:
break;
default:
{
debug(1,
MISSING_COMMAND_ERR_MSG,
nxt_path.c_str());
wperror(L"access");
}
}
}
}
}
errno = err;
return false;
}
bool path_get_path(const wcstring &cmd, wcstring *out_path, const env_vars_snapshot_t &vars)
{
return path_get_path_core(cmd, out_path, vars.get(L"PATH"));
}
bool path_get_path(const wcstring &cmd, wcstring *out_path)
{
return path_get_path_core(cmd, out_path, env_get_string(L"PATH"));
}
bool path_get_cdpath_string(const wcstring &dir_str, wcstring &result, const env_var_t &cdpath)
{
wchar_t *res = 0;
int err = ENOENT;
bool success = false;
const wchar_t *const dir = dir_str.c_str();
if (dir[0] == L'/'|| (wcsncmp(dir, L"./", 2)==0))
{
struct stat buf;
if (wstat(dir, &buf) == 0)
{
if (S_ISDIR(buf.st_mode))
{
result = dir_str;
success = true;
}
else
{
err = ENOTDIR;
}
}
}
else
{
wcstring path = L".";
// Respect CDPATH
env_var_t cdpath = env_get_string(L"CDPATH");
if (! cdpath.missing_or_empty())
{
path = cdpath.c_str();
}
wcstokenizer tokenizer(path, ARRAY_SEP_STR);
wcstring next_path;
while (tokenizer.next(next_path))
{
expand_tilde(next_path);
if (next_path.size() == 0) continue;
wcstring whole_path = next_path;
append_path_component(whole_path, dir);
struct stat buf;
if (wstat(whole_path, &buf) == 0)
{
if (S_ISDIR(buf.st_mode))
{
result = whole_path;
success = true;
break;
}
else
{
err = ENOTDIR;
}
}
else
{
if (lwstat(whole_path, &buf) == 0)
{
err = EROTTEN;
}
}
}
}
if (!success)
{
errno = err;
}
return res;
}
bool path_get_cdpath(const wcstring &dir, wcstring *out, const wchar_t *wd, const env_vars_snapshot_t &env_vars)
{
int err = ENOENT;
if (dir.empty())
return false;
if (wd)
{
size_t len = wcslen(wd);
assert(wd[len - 1] == L'/');
}
wcstring_list_t paths;
if (dir.at(0) == L'/')
{
/* Absolute path */
paths.push_back(dir);
}
else if (string_prefixes_string(L"./", dir) ||
string_prefixes_string(L"../", dir) ||
dir == L"." || dir == L"..")
{
/* Path is relative to the working directory */
wcstring path;
if (wd)
path.append(wd);
path.append(dir);
paths.push_back(path);
}
else
{
// Respect CDPATH
env_var_t path = env_vars.get(L"CDPATH");
if (path.missing_or_empty())
path = L"."; //We'll change this to the wd if we have one
wcstring nxt_path;
wcstokenizer tokenizer(path, ARRAY_SEP_STR);
while (tokenizer.next(nxt_path))
{
if (nxt_path == L"." && wd != NULL)
{
// nxt_path is just '.', and we have a working directory, so use the wd instead
// TODO: if nxt_path starts with ./ we need to replace the . with the wd
nxt_path = wd;
}
expand_tilde(nxt_path);
// debug( 2, L"woot %ls\n", expanded_path.c_str() );
if (nxt_path.empty())
continue;
wcstring whole_path = nxt_path;
append_path_component(whole_path, dir);
paths.push_back(whole_path);
}
}
bool success = false;
for (wcstring_list_t::const_iterator iter = paths.begin(); iter != paths.end(); ++iter)
{
struct stat buf;
const wcstring &dir = *iter;
if (wstat(dir, &buf) == 0)
{
if (S_ISDIR(buf.st_mode))
{
success = true;
if (out)
out->assign(dir);
break;
}
else
{
err = ENOTDIR;
}
}
}
if (! success)
errno = err;
return success;
}
bool path_can_be_implicit_cd(const wcstring &path, wcstring *out_path, const wchar_t *wd, const env_vars_snapshot_t &vars)
{
wcstring exp_path = path;
expand_tilde(exp_path);
bool result = false;
if (string_prefixes_string(L"/", exp_path) ||
string_prefixes_string(L"./", exp_path) ||
string_prefixes_string(L"../", exp_path) ||
string_suffixes_string(L"/", exp_path) ||
exp_path == L"..")
{
/* These paths can be implicit cd, so see if you cd to the path. Note that a single period cannot (that's used for sourcing files anyways) */
result = path_get_cdpath(exp_path, out_path, wd, vars);
}
return result;
}
static wcstring path_create_config()
{
bool done = false;
wcstring res;
const env_var_t xdg_dir = env_get_string(L"XDG_CONFIG_HOME");
if (! xdg_dir.missing())
{
res = xdg_dir + L"/fish";
if (!create_directory(res))
{
done = true;
}
}
else
{
const env_var_t home = env_get_string(L"HOME");
if (! home.missing())
{
res = home + L"/.config/fish";
if (!create_directory(res))
{
done = true;
}
}
}
if (! done)
{
res.clear();
debug(0, _(L"Unable to create a configuration directory for fish. Your personal settings will not be saved. Please set the $XDG_CONFIG_HOME variable to a directory where the current user has write access."));
}
return res;
}
/* Cache the config path */
bool path_get_config(wcstring &path)
{
static const wcstring result = path_create_config();
path = result;
return ! result.empty();
}
__attribute__((unused))
static void replace_all(wcstring &str, const wchar_t *needle, const wchar_t *replacement)
{
size_t needle_len = wcslen(needle);
size_t offset = 0;
while ((offset = str.find(needle, offset)) != wcstring::npos)
{
str.replace(offset, needle_len, replacement);
offset += needle_len;
}
}
void path_make_canonical(wcstring &path)
{
// Ignore trailing slashes, unless it's the first character
size_t len = path.size();
while (len > 1 && path.at(len - 1) == L'/')
len--;
// Turn runs of slashes into a single slash
size_t trailing = 0;
bool prev_was_slash = false;
for (size_t leading = 0; leading < len; leading++)
{
wchar_t c = path.at(leading);
bool is_slash = (c == '/');
if (! prev_was_slash || ! is_slash)
{
// This is either the first slash in a run, or not a slash at all
path.at(trailing++) = c;
}
prev_was_slash = is_slash;
}
assert(trailing <= len);
if (trailing < len)
path.resize(trailing);
}
bool paths_are_equivalent(const wcstring &p1, const wcstring &p2)
{
if (p1 == p2)
return true;
size_t len1 = p1.size(), len2 = p2.size();
// Ignore trailing slashes after the first character
while (len1 > 1 && p1.at(len1 - 1) == L'/') len1--;
while (len2 > 1 && p2.at(len2 - 1) == L'/') len2--;
// Start walking
size_t idx1 = 0, idx2 = 0;
while (idx1 < len1 && idx2 < len2)
{
wchar_t c1 = p1.at(idx1), c2 = p2.at(idx2);
// If the characters are different, the strings are not equivalent
if (c1 != c2)
break;
idx1++;
idx2++;
// If the character was a slash, walk forwards until we hit the end of the string, or a non-slash
// Note the first condition is invariant within the loop
while (c1 == L'/' && idx1 < len1 && p1.at(idx1) == L'/') idx1++;
while (c2 == L'/' && idx2 < len2 && p2.at(idx2) == L'/') idx2++;
}
// We matched if we consumed all of the characters in both strings
return idx1 == len1 && idx2 == len2;
}
bool path_is_valid(const wcstring &path, const wcstring &working_directory)
{
bool path_is_valid;
/* Some special paths are always valid */
if (path.empty())
{
path_is_valid = false;
}
else if (path == L"." || path == L"./")
{
path_is_valid = true;
}
else if (path == L".." || path == L"../")
{
path_is_valid = (! working_directory.empty() && working_directory != L"/");
}
else if (path.at(0) != '/')
{
/* Prepend the working directory. Note that we know path is not empty here. */
wcstring tmp = working_directory;
tmp.append(path);
path_is_valid = (0 == waccess(tmp, F_OK));
}
else
{
/* Simple check */
path_is_valid = (0 == waccess(path, F_OK));
}
return path_is_valid;
}
bool paths_are_same_file(const wcstring &path1, const wcstring &path2)
{
if (paths_are_equivalent(path1, path2))
return true;
struct stat s1, s2;
if (wstat(path1, &s1) == 0 && wstat(path2, &s2) == 0)
{
return s1.st_ino == s2.st_ino && s1.st_dev == s2.st_dev;
}
else
{
return false;
}
}