journalctl: use _COMM= match for scripts

In case of scripts, _EXE is set to the interpreter name, and
_COMM is set based on the file name. Add a match for _COMM,
and _EXE if the interpreter is not a link (e.g. for yum,
the interpreter is /usr/bin/python, but it is a link to
/usr/bin/python2, which in turn is a link to /usr/bin/python2.7,
at least on Fedora, so we end up with _EXE=/usr/bin/python2.7).
I don't think that such link chasing makes sense, because
the final _EXE name is more likely to change.

2 files changed, 31 insertions, 0 deletions

diff --git a/src/shared/fileio.c b/src/shared/fileio.c
index dc13c9ee63..2b1dab8053 100644
--- a/src/shared/fileio.c
+++ b/src/shared/fileio.c
@@ -593,3 +593,32 @@ int write_env_file(const char *fname, char **l) {
 
         return r;
 }
+
+int executable_is_script(const char *path, char **interpreter) {
+        int r;
+        char _cleanup_free_ *line = NULL;
+        int len;
+        char *ans;
+
+        assert(path);
+
+        r = read_one_line_file(path, &line);
+        if (r < 0)
+                return r;
+
+        if (!startswith(line, "#!"))
+                return 0;
+
+        ans = strstrip(line + 2);
+        len = strcspn(ans, " \t");
+
+        if (len == 0)
+                return 0;
+
+        ans = strndup(ans, len);
+        if (!ans)
+                return -ENOMEM;
+
+        *interpreter = ans;
+        return 1;
+}
diff --git a/src/shared/fileio.h b/src/shared/fileio.h
index 0ca6878ea4..a0aae28bae 100644
--- a/src/shared/fileio.h
+++ b/src/shared/fileio.h
@@ -35,3 +35,5 @@ int read_full_file(const char *fn, char **contents, size_t *size);
 int parse_env_file(const char *fname, const char *separator, ...) _sentinel_;
 int load_env_file(const char *fname, const char *separator, char ***l);
 int write_env_file(const char *fname, char **l);
+
+int executable_is_script(const char *path, char **interpreter);