Re: [PATCH] findprog: Support searching in a specified path string
Hi Paul,
> note that
> on Windows, which is the only place this matters, so far, IIRC it is
> illegal to use "prog.exe.exe" so if an extension is already provided
> the system won't search again
Indeed, the native Windows execlp() function behaves like this:
- If the caller specifies "prog.exe.exe" or "prog.foo.exe" and
that file will be exists, it will be found and executed.
- If the caller specifies "prog.exe" or "prog.foo" but that file
does not exist, the search will NOT extend to "prog.exe.exe" or
"prog.foo.exe", respectively.
I'm updating the code (patch below).
> I actually don't see any need for this optimization, especially
> compared to the added complexity of the API and docs: the suffix check
> needs to be done somewhere after all.
But on platforms like Cygwin, it would be done twice.
2019-09-14 Bruno Haible
findprog-in: Better mimic the system on native Windows.
Reported by Paul Smith .
* lib/findprog-in.c (find_in_given_path): On native Windows, don't try
non-empty suffixes when the file name already contains a '.'.
diff --git a/lib/findprog-in.c b/lib/findprog-in.c
index 99b3c31..d601e06 100644
--- a/lib/findprog-in.c
+++ b/lib/findprog-in.c
@@ -118,8 +118,9 @@ find_in_given_path (const char *progname, const char *path,
const char *suffix = suffixes[i];
#if defined _WIN32 && !defined __CYGWIN__ /* Native Windows */
-/* File names without a '.' are not considered executable. */
-if (*suffix != '\0' || strchr (progbasename, '.') != NULL)
+/* File names without a '.' are not considered executable, and
+ for file names with a '.' no additional suffix is tried. */
+if ((*suffix != '\0') != (strchr (progbasename, '.') != NULL))
#endif
{
/* Concatenate progname and suffix. */
@@ -185,8 +186,9 @@ find_in_given_path (const char *progname, const char *path,
const char *suffix = suffixes[i];
#if defined _WIN32 && !defined __CYGWIN__ /* Native Windows */
-/* File names without a '.' are not considered executable. */
-if (*suffix != '\0' || strchr (progname, '.') != NULL)
+/* File names without a '.' are not considered executable, and
+ for file names with a '.' no additional suffix is tried. */
+if ((*suffix != '\0') != (strchr (progname, '.') != NULL))
#endif
{
/* Concatenate dir, progname, and suffix. */
make autoconf tests work with -Werror=implicit-function-declaration
There are indications that future GCC versions may be stricter regarding
invocations of undeclared functions. [1] Configuring with
CC="gcc -Werror=implicit-function-declaration"
is a way to exercise similar functionality with released GCCs.
So, what I did is
1. create a testdir of all of gnulib,
2. configure it once with CC="gcc" and once with
CC="gcc -Werror=implicit-function-declaration", both with option '-C',
3. compare the resulting config.cache files.
I got differences in the cache variables
gl_cv_func_ptsname_sets_errno
gt_cv_locale_tr_utf8
This patch fixes the issues.
[1] https://lists.gnu.org/archive/html/bug-gettext/2019-09/msg00012.html
2019-09-14 Bruno Haible
Make autoconf tests work with -Werror=implicit-function-declaration.
* m4/locale-tr.m4 (gt_LOCALE_TR_UTF8): Include , for
towupper() declaration.
* m4/ptsname.m4 (gl_FUNC_PTSNAME): Include , for ptsname()
declaration.
diff --git a/m4/locale-tr.m4 b/m4/locale-tr.m4
index aeb2419..4c413f0 100644
--- a/m4/locale-tr.m4
+++ b/m4/locale-tr.m4
@@ -1,4 +1,4 @@
-# locale-tr.m4 serial 11
+# locale-tr.m4 serial 12
dnl Copyright (C) 2003, 2005-2019 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -21,6 +21,7 @@ changequote(,)dnl
#endif
#include
#include
+#include
struct tm t;
char buf[16];
int main () {
diff --git a/m4/ptsname.m4 b/m4/ptsname.m4
index 5033d90..04bfd3b 100644
--- a/m4/ptsname.m4
+++ b/m4/ptsname.m4
@@ -1,4 +1,4 @@
-# ptsname.m4 serial 7
+# ptsname.m4 serial 8
dnl Copyright (C) 2010-2019 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -19,10 +19,12 @@ AC_DEFUN([gl_FUNC_PTSNAME],
AC_CACHE_CHECK([whether ptsname sets errno on failure],
[gl_cv_func_ptsname_sets_errno],
[AC_RUN_IFELSE(
- [AC_LANG_PROGRAM([[#include
- ]], [[
- return ptsname (-1) || !errno;
- ]])],
+ [AC_LANG_PROGRAM([[
+ #include
+ #include
+]], [[
+ return ptsname (-1) || !errno;
+]])],
[gl_cv_func_ptsname_sets_errno=yes],
[gl_cv_func_ptsname_sets_errno=no],
[case "$host_os" in
[PATCH] findprog-in: Set errno to indicate why NULL was returned.
Set errno to either ENOENT if the program was not found, or another
error if a program was found but was no suitable (i.e., EACCES).
* modules/findprog: Depend on errno.
* lib/findprog-in.c (find_in_given_path): Save errno if it is not ENOENT
and reset errno before returning NULL.
* lib/findprog.h (find_in_given_path): Update the documentation.
---
lib/findprog-in.c | 9 +
lib/findprog.h | 20
modules/findprog-in | 1 +
3 files changed, 22 insertions(+), 8 deletions(-)
diff --git a/lib/findprog-in.c b/lib/findprog-in.c
index d601e060d..8ea03f8f7 100644
--- a/lib/findprog-in.c
+++ b/lib/findprog-in.c
@@ -24,6 +24,7 @@
#include
#include
#include
+#include
#include
#include "filename.h"
@@ -74,6 +75,8 @@ const char *
find_in_given_path (const char *progname, const char *path,
bool optimize_for_exec)
{
+ int saved_errno = ENOENT;
+
{
bool has_slash = false;
{
@@ -142,11 +145,14 @@ find_in_given_path (const char *progname, const char
*path,
else
return progpathname;
}
+else if (errno != ENOENT)
+ saved_errno = errno;
free (progpathname);
}
}
+errno = saved_errno;
return NULL;
}
}
@@ -221,6 +227,8 @@ find_in_given_path (const char *progname, const char *path,
free (path_copy);
return progpathname;
}
+else if (errno != ENOENT)
+ saved_errno = errno;
free (progpathname);
}
@@ -234,5 +242,6 @@ find_in_given_path (const char *progname, const char *path,
free (path_copy);
}
+ errno = saved_errno;
return NULL;
}
diff --git a/lib/findprog.h b/lib/findprog.h
index f7b44071f..b1b6caa5f 100644
--- a/lib/findprog.h
+++ b/lib/findprog.h
@@ -41,14 +41,18 @@ extern const char *find_in_path (const char *progname);
directory. A null PATH is equivalent to an empty PATH, that is, to the
singleton list that contains only the current directory.
Determines the pathname that would be called by execlp/execvp of PROGNAME.
- - If successful, it returns a pathname containing a slash (either absolute
- or relative to the current directory). The returned string can be used
- with either execl/execv or execlp/execvp. It is freshly malloc()ed if it
- is != PROGNAME.
- - Otherwise, it returns NULL.
- If OPTIMIZE_FOR_EXEC is true, the function saves some work, under the
- assumption that the resulting pathname will not be accessed directly,
- only through execl/execv or execlp/execvp. */
+ On systems which support executable suffixes these are checked, if PROGNAME
+ does not already contain a suffix.
+ Returns either PROGNAME, or a freshly malloc()ed string, or NULL. If NULL
+ is returned then errno is set (ENOENT, EACCES, etc.)
+ If PROGNAME contains a slash ('/' on POSIX; '/' or '\' on Windows) then:
+ - If OPTIMIZE_FOR_EXEC is true returns PROGNAME without checking suffixes
+ or existence under the assumption that the resulting pathname will be
+ used with execl/execv/execlp/execvp.
+ - Else if PROGNAME refers an executable program it is returned.
+ - Else NULL is returned and errno is set.
+ Otherwise PATH is searched and the pathname is returned if found, or
+ returns NULL and errno is set. */
extern const char *find_in_given_path (const char *progname, const char *path,
bool optimize_for_exec);
diff --git a/modules/findprog-in b/modules/findprog-in
index ce7faa50e..d38e6f2be 100644
--- a/modules/findprog-in
+++ b/modules/findprog-in
@@ -9,6 +9,7 @@ m4/eaccess.m4
Depends-on:
stdbool
+errno
filename
xalloc
xconcat-filename
--
2.18.0
Re: [PATCH] findprog-in: Set errno to indicate why NULL was returned.
On Sat, 2019-09-14 at 15:35 -0400, Paul Smith wrote: > Set errno to either ENOENT if the program was not found, or another > error if a program was found but was no suitable (i.e., EACCES). Without this change it's impossible for a program to show the correct error message when the program is found on the path, but is not executable.
