This is a utility function we can use to see whether an executable is
available.
---
util/Makefile.local | 2 +-
util/search-path.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++
util/search-path.h | 24 +++++++++++++++++++++++
3 files changed, 80 insertions(+), 1 deletion(-)
create mode 100644 util/search-path.c
create mode 100644 util/search-path.h
diff --git a/util/Makefile.local b/util/Makefile.local
index 905f237..8b2b91b 100644
--- a/util/Makefile.local
+++ b/util/Makefile.local
@@ -5,7 +5,7 @@ extra_cflags += -I$(srcdir)/$(dir)
libutil_c_srcs := $(dir)/xutil.c $(dir)/error_util.c $(dir)/hex-escape.c \
$(dir)/string-util.c $(dir)/talloc-extra.c
$(dir)/zlib-extra.c \
- $(dir)/util.c
+ $(dir)/util.c $(dir)/search-path.c
libutil_modules := $(libutil_c_srcs:.c=.o)
diff --git a/util/search-path.c b/util/search-path.c
new file mode 100644
index 0000000..5eac367
--- /dev/null
+++ b/util/search-path.c
@@ -0,0 +1,55 @@
+#include "search-path.h"
+#include <stdlib.h>
+#include <talloc.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+
+notmuch_bool_t
+test_for_executable(const char* exename)
+{
+ char *c = NULL, *save = NULL, *tok;
+ size_t n;
+ int dfd = -1;
+ notmuch_bool_t ret = FALSE;
+
+ if (strchr(exename, '/')) {
+ if (0 == access(exename, X_OK))
+ return TRUE;
+ else
+ return FALSE;
+ }
+
+ c = getenv("PATH");
+ if (c)
+ c = talloc_strdup(NULL, c);
+ else {
+ n = confstr(_CS_PATH, NULL, 0);
+ c = (char*)talloc_size(NULL, n);
+ if (!c)
+ return FALSE;
+ confstr(_CS_PATH, c, n);
+ }
+
+ tok = strtok_r(c, ":", &save);
+ while (tok) {
+ dfd = open(tok, O_DIRECTORY | O_RDONLY);
+ if (dfd != -1) {
+ if (!faccessat(dfd, exename, X_OK, 0)) {
+ ret = TRUE;
+ goto done;
+ }
+ close(dfd);
+ }
+ tok = strtok_r(NULL, ":", &save);
+ }
+done:
+ if (dfd != -1)
+ close(dfd);
+ if (c)
+ talloc_free(c);
+ return ret;
+}
diff --git a/util/search-path.h b/util/search-path.h
new file mode 100644
index 0000000..727d0b3
--- /dev/null
+++ b/util/search-path.h
@@ -0,0 +1,24 @@
+#ifndef _SEARCH_PATH_H
+#define _SEARCH_PATH_H
+
+#include "notmuch.h"
+
+/* can an executable be found with the given name?
+ *
+ * Return TRUE only if we can find something to execute with the
+ * associated name.
+ *
+ * if the name has a '/' in it, we look for it directly with
+ * access(exename, X_OK).
+ *
+ * otherwise, we look for it in $PATH (or in confstr(_CS_PATH), if
+ * $PATH is unset).
+ *
+ * This should match the logic for execvp (as well as matching user
+ * expectations, hopefully).
+ */
+
+notmuch_bool_t
+test_for_executable(const char *exename);
+
+#endif
--
2.7.0.rc3
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