[Libguestfs] [PATCH nbdkit 1/2] tmpdisk: Generate the default command from a shell script fragment.

[Richard W.M. Jones]

Neutral refactoring.  Makes the code a bit easier to handle and
simplifies future commits.
---
 plugins/tmpdisk/Makefile.am           | 17 ++++++++-
 plugins/tmpdisk/tmpdisk.c             | 22 +++---------
 plugins/tmpdisk/default-command.sh.in | 51 +++++++++++++++++++++++++++
 .gitignore                            |  1 +
 4 files changed, 72 insertions(+), 19 deletions(-)

diff --git a/plugins/tmpdisk/Makefile.am b/plugins/tmpdisk/Makefile.am
index 34061771..20aeb05f 100644
--- a/plugins/tmpdisk/Makefile.am
+++ b/plugins/tmpdisk/Makefile.am
@@ -31,11 +31,26 @@
 
 include $(top_srcdir)/common-rules.mk
 
-EXTRA_DIST = nbdkit-tmpdisk-plugin.pod
+EXTRA_DIST = \
+	default-command.sh.in \
+	nbdkit-tmpdisk-plugin.pod \
+	$(NULL)
+
+# The default command we use (if we don't use command=) comes from a
+# shell script which is turned into a C source file.
+BUILT_SOURCES = default-command.c
+
+default-command.c: default-command.sh.in Makefile
+	rm -f $@ $@-t
+	echo 'const char *command =' > $@-t
+	$(SED) -e '/^#/d' -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/' < $< >> $@-t
+	echo ';' >> $@-t
+	mv $@-t $@
 
 plugin_LTLIBRARIES = nbdkit-tmpdisk-plugin.la
 
 nbdkit_tmpdisk_plugin_la_SOURCES = \
+	default-command.c \
 	tmpdisk.c \
 	$(top_srcdir)/include/nbdkit-plugin.h \
 	$(NULL)
diff --git a/plugins/tmpdisk/tmpdisk.c b/plugins/tmpdisk/tmpdisk.c
index a5aacc9d..5e8df151 100644
--- a/plugins/tmpdisk/tmpdisk.c
+++ b/plugins/tmpdisk/tmpdisk.c
@@ -55,24 +55,10 @@ static int64_t size = -1;
 static const char *label = NULL;
 static const char *type = "ext4";
 
-static const char *command =
-  "labelopt='-L'\n"
-  "case \"$type\" in\n"
-  "    ext?)\n"
-  "        extra='-F' ;;\n"
-  "    *fat|msdos)\n"
-  "        extra='-I' ;;\n"
-  "    ntfs)\n"
-  "        extra='-Q -F'\n"
-  "        labelopt='-n' ;;\n"
-  "    xfs)\n"
-  "        extra='-f' ;;\n"
-  "esac\n"
-  "if [ \"x$label\" = \"x\" ]; then\n"
-  "    mkfs -t \"$type\" $extra \"$disk\"\n"
-  "else\n"
-  "    mkfs -t \"$type\" $extra $labelopt \"$label\" \"$disk\"\n"
-  "fi\n";
+/* This comes from default-command.c which is generated from
+ * default-command.sh.in.
+ */
+extern const char *command;
 
 static void
 tmpdisk_load (void)
diff --git a/plugins/tmpdisk/default-command.sh.in b/plugins/tmpdisk/default-command.sh.in
new file mode 100644
index 00000000..251e0b7b
--- /dev/null
+++ b/plugins/tmpdisk/default-command.sh.in
@@ -0,0 +1,51 @@
+# nbdkit
+# -*- mode: shell-script -*-
+# Copyright (C) 2017-2020 Red Hat Inc.
+#
+# 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.
+
+labelopt='-L'
+
+case "$type" in
+    ext?)
+        extra='-F' ;;
+    *fat|msdos)
+        extra='-I' ;;
+    ntfs)
+        extra='-Q -F'
+        labelopt='-n' ;;
+    xfs)
+        extra='-f' ;;
+esac
+
+if [ "x$label" = "x" ]; then
+    mkfs -t "$type" $extra "$disk"
+else
+    mkfs -t "$type" $extra $labelopt "$label" "$disk"
+fi
diff --git a/.gitignore b/.gitignore
index 4bb035e1..c44fb40d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -76,6 +76,7 @@ plugins/*/*.3
 /plugins/rust/Cargo.toml
 /plugins/rust/target
 /plugins/tar/nbdkit-tar-plugin
+/plugins/tmpdisk/default-command.c
 /podwrapper.pl
 /server/nbdkit
 /server/nbdkit.pc
-- 
2.25.0