Commit 7df09064a4 ("server: Explain what to do if plugin/filter loading fails") added a useful tip for how to install the plugin or filter package from common Linux distros. However it was not very selective and might suggest impossible package names. Fix this by only printing the tip if it's a plausible package name. Added { ... } for clarity in the code. Updates: commit 7df09064a4e993a74d2d4421b70b272e7121c929 --- server/main.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/server/main.c b/server/main.c index 7c9dc27626..f3cb604cbd 100644 --- a/server/main.c +++ b/server/main.c @@ -63,6 +63,7 @@ #include <dlfcn.h> +#include "ascii-ctype.h" #include "ascii-string.h" #include "exit-with-parent.h" #include "nbd-protocol.h" @@ -982,6 +983,27 @@ make_uri (void) return r; } +/* Is it the name of a possible nbdkit-<name>-plugin or + * nbdkit-<name>-filter that might be a Fedora or Debian package? + * This matches more than all possible names, but it's just a guide + * for help output. + */ +static int +is_possible_package_name (const char *name) +{ + size_t i, n = strlen (name); + + for (i = 0; i < n; ++i) { + char c = name[i]; + if (ascii_isalnum (c)) + continue; + if (c == '-' || c == '_' || c == '.') + continue; + return 0; + } + return 1; +} + /* Common error handling for dlopen failures in open_plugin_so or * open_filter_so. * @@ -1001,13 +1023,14 @@ failed_to_load_error (const char *what, { fprintf (stderr, "%s: error: cannot open %s '%s': %s\n", program_name, what, filename, dlerror ()); - if (short_name) + if (short_name && is_possible_package_name (short_name)) { fprintf (stderr, "\n" "To add this functionality you might need to install a separate\n" "%s package such as nbdkit-%s-%s (Fedora) or\n" "nbdkit-%s-%s (Debian).\n", what, short_name, what, what, short_name); + } fprintf (stderr, "\n" "Use '%s --help' or " -- 2.44.0

--- tests/Makefile.am | 3 ++ tests/test-shebang-crlf.sh | 59 ++++++++++++++++++++++++++++++++++++++ tests/shebang-crlf.py | 2 ++ 3 files changed, 64 insertions(+) diff --git a/tests/Makefile.am b/tests/Makefile.am index f03ed2cb9a..16f7d408b0 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -1287,6 +1287,7 @@ TESTS += \ test-python-peer.sh \ test-python-thread-model.sh \ test-shebang-python.sh \ + test-shebang-crlf.sh \ $(NULL) EXTRA_DIST += \ python-error.py \ @@ -1298,6 +1299,7 @@ EXTRA_DIST += \ python-peer.py \ python-thread-model.py \ shebang.py \ + shebang-crlf.py \ test-python-error.sh \ test-python-exception.sh \ test-python-export-name.sh \ @@ -1309,6 +1311,7 @@ EXTRA_DIST += \ test-python-thread-model.sh \ test-python.sh \ test-shebang-python.sh \ + test-shebang-crlf.sh \ test_python.py \ $(NULL) diff --git a/tests/test-shebang-crlf.sh b/tests/test-shebang-crlf.sh new file mode 100755 index 0000000000..c11d5c0b89 --- /dev/null +++ b/tests/test-shebang-crlf.sh @@ -0,0 +1,59 @@ +#!/usr/bin/env bash +# nbdkit +# Copyright Red Hat +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# * Neither the name of Red Hat nor the names of its contributors may be +# used to endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. + +# See also: shebang-crlf.py +# +# CRLF shebang line used to cause a confusing error message: +# -plugin.so: cannot open shared object file: No such file or directoryon +# (In fact what is happening is that the first part of the message +# is hidden before a CR character.) +# +# We still expect this script to fail, but for the error not to be +# confusing. + +source ./functions.sh +set -e +set -x + +script=$abs_top_srcdir/tests/shebang-crlf.py +if test ! -x "$script"; then + echo "$0: could not locate $script or not executable" + exit 1 +fi + +out="test-shebang-crlf.out" +rm -f $out +cleanup_fn rm -f $out + +$script --verbose --dump-plugin 2> $out ||: +cat $out +grep -E 'python\\r' $out diff --git a/tests/shebang-crlf.py b/tests/shebang-crlf.py new file mode 100755 index 0000000000..2713f2c3cb --- /dev/null +++ b/tests/shebang-crlf.py @@ -0,0 +1,2 @@ +#!../nbdkit python +# See also: test-shebang-crlf.sh -- 2.44.0

On Thu, Apr 18, 2024 at 03:32:33PM -0500, Eric Blake wrote: Yes I think that's a better idea. I'll respin this (probably not this week) with the suggested change. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW