Fix segfault when SHLVL env var is not available (#52)

diff --git a/nnn.c b/nnn.c
index 450474dff2715f9c09b6f9b3e26766d47ff83734..28335898c81c27680249e7e0e4deb6c78661fc6c 100644 (file)
--- a/nnn.c
+++ b/nnn.c
@@ -559,6 +559,7 @@ spawn(char *file, char *arg1, char *arg2, char *dir, uchar flag)
 {
        pid_t pid;
        int status;
+       char *shlvl;
 
        if (flag & F_NORMAL)
                exitcurses();
@@ -568,10 +569,12 @@ spawn(char *file, char *arg1, char *arg2, char *dir, uchar flag)
                if (dir != NULL)
                        status = chdir(dir);
 
+               shlvl = getenv("SHLVL");
+
                /* Show a marker (to indicate nnn spawned shell) */
-               if (flag & F_MARKER) {
+               if (flag & F_MARKER && shlvl != NULL) {
                        printf("\n +-++-++-+\n | n n n |\n +-++-++-+\n\n");
-                       printf("Spawned shell level: %d\n", atoi(getenv("SHLVL")) + 1);
+                       printf("Spawned shell level: %d\n", atoi(shlvl) + 1);
                }
 
                /* Suppress stdout and stderr */