8:52 a.m.
We do this by defining DB_DUMP unconditionally and then testing the
special exit code given by the shell if the command is not found (see
http://www.tldp.org/LDP/abs/html/exitcodes.html).
Packagers may either:
(1) Provide db_dump as a build requirement, but make it a weak
dependency at runtime, or:
(2) Not provide db_dump at build time, but define DB_DUMP to its
expected path when configuring, eg:
DB_DUMP=/usr/bin/db_dump ./configure
which will then be compiled into the library and used if available at
runtime (or ignored as in case (1) if not available at runtime).
---
lib/dbdump.c | 11 +++++++----
lib/inspect-apps.c | 8 --------
m4/guestfs-progs.m4 | 8 ++------
3 files changed, 9 insertions(+), 18 deletions(-)
diff --git a/lib/dbdump.c b/lib/dbdump.c
index 7c17ce6b3..3ec11f2bd 100644
--- a/lib/dbdump.c
+++ b/lib/dbdump.c
@@ -31,8 +31,6 @@
#include "guestfs.h"
#include "guestfs-internal.h"
-#if defined(DB_DUMP)
-
static void read_db_dump_line (guestfs_h *g, void *datav, const char *line, size_t len);
static unsigned char *convert_hex_to_binary (guestfs_h *g, const char *hex, size_t
hexlen, size_t *binlen_rtn);
@@ -75,6 +73,13 @@ guestfs_int_read_db_dump (guestfs_h *g,
if (r == -1)
return -1;
+ if (WIFEXITED (r) && WEXITSTATUS (r) == 127) {
+ /* Allow the command to be missing at runtime so that packagers can
+ * use weak dependencies. In this case it's not an error, we
+ * return an empty list.
+ */
+ return 0;
+ }
if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) {
guestfs_int_external_command_failed (g, r, DB_DUMP, NULL);
return -1;
@@ -225,5 +230,3 @@ convert_hex_to_binary (guestfs_h *g, const char *hex, size_t hexlen,
*binlen_rtn = binlen;
return bin;
}
-
-#endif /* defined(DB_DUMP) */
diff --git a/lib/inspect-apps.c b/lib/inspect-apps.c
index f0cf16b38..57428a3ba 100644
--- a/lib/inspect-apps.c
+++ b/lib/inspect-apps.c
@@ -45,9 +45,7 @@
#include "guestfs-internal-actions.h"
#include "structs-cleanups.h"
-#ifdef DB_DUMP
static struct guestfs_application2_list *list_applications_rpm (guestfs_h *g, const char
*root);
-#endif
static struct guestfs_application2_list *list_applications_deb (guestfs_h *g, const char
*root);
static struct guestfs_application2_list *list_applications_pacman (guestfs_h *g, const
char *root);
static struct guestfs_application2_list *list_applications_apk (guestfs_h *g, const char
*root);
@@ -121,11 +119,9 @@ guestfs_impl_inspect_list_applications2 (guestfs_h *g, const char
*root)
if (STREQ (type, "linux") || STREQ (type, "hurd")) {
if (STREQ (package_format, "rpm")) {
-#ifdef DB_DUMP
ret = list_applications_rpm (g, root);
if (ret == NULL)
return NULL;
-#endif
}
else if (STREQ (package_format, "deb")) {
ret = list_applications_deb (g, root);
@@ -163,8 +159,6 @@ guestfs_impl_inspect_list_applications2 (guestfs_h *g, const char
*root)
return ret;
}
-#ifdef DB_DUMP
-
/* This data comes from the Name database, and contains the application
* names and the first 4 bytes of each link field.
*/
@@ -409,8 +403,6 @@ list_applications_rpm (guestfs_h *g, const char *root)
return NULL;
}
-#endif /* defined DB_DUMP */
-
static struct guestfs_application2_list *
list_applications_deb (guestfs_h *g, const char *root)
{
diff --git a/m4/guestfs-progs.m4 b/m4/guestfs-progs.m4
index 1f0a4c1f6..1455be550 100644
--- a/m4/guestfs-progs.m4
+++ b/m4/guestfs-progs.m4
@@ -66,12 +66,8 @@ AM_CONDITIONAL([HAVE_PO4A], [test "x$PO4A" !=
"xno"])
dnl Check for db_dump, db_load (optional).
GUESTFS_FIND_DB_TOOL([DB_DUMP], [dump])
GUESTFS_FIND_DB_TOOL([DB_LOAD], [load])
-if test "x$DB_DUMP" != "xno"; then
- AC_DEFINE_UNQUOTED([DB_DUMP],["$DB_DUMP"],[Name of db_dump program.])
-fi
-if test "x$DB_LOAD" != "xno"; then
- AC_DEFINE_UNQUOTED([DB_LOAD],["$DB_LOAD"],[Name of db_load program.])
-fi
+AC_DEFINE_UNQUOTED([DB_DUMP],["$DB_DUMP"],[Name of db_dump program.])
+AC_DEFINE_UNQUOTED([DB_LOAD],["$DB_LOAD"],[Name of db_load program.])
dnl Check for netpbm programs (optional).
AC_PATH_PROGS([PBMTEXT],[pbmtext],[no])
--
2.13.2