Handle 32bit signed overflow.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/modbuslog.c b/src/modbuslog.c
index e7ccb05..1e849bb 100644
--- a/src/modbuslog.c
+++ b/src/modbuslog.c
@@ -309,7 +309,12 @@ int main(int argc, char *argv[]) {
 				int intervalid;
 				FILE *intervalfile = fopen("/var/modbuslog/interval/interval.txt", "r+");
 				fscanf(intervalfile, "%d", &intervalid);
-				intervalid++;
+				//handle 32bit signed overflow
+				if(intervalid==2147483647){
+					intervalid=0;
+				}else{
+					intervalid++;
+				}
 				rewind(intervalfile);
 				fprintf(intervalfile, "%d", intervalid);
 				fclose(intervalfile);