inode numbers are expected to be positive. Casting them to a signed type may result in printing negative values. E.g. running example program on the following file: $ ls -li test.txt 9280843260537405888 -r--r--r-- 1 kbukin hardware 300 Jul 21 06:36 test.txt resutls in the following output: $ ./example test.txt ID of containing device: [0,480] File type: regular file I-node number: -9165900813172145728 Mode: 100444 (octal) Link count: 1 Ownership: UID=2743 GID=30 Preferred I/O block size: 32768 bytes File size: 300 bytes Blocks allocated: 8 Last status change: Tue Jul 21 06:36:50 2020 Last file access: Sat Sep 12 14:13:38 2020 Last file modification: Tue Jul 21 06:36:50 2020 Such erroneous reporting happens for inode values greater than maximum value which can be stored in signed long. Casting does not seem to be necessary here. Printing inode as unsigned long fixes the issue. --- man2/stat.2 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/man2/stat.2 b/man2/stat.2 index 7e5417480..76997bcbe 100644 --- a/man2/stat.2 +++ b/man2/stat.2 @@ -681,7 +681,7 @@ main(int argc, char *argv[]) default: printf("unknown?\en"); break; } - printf("I\-node number: %ld\en", (long) sb.st_ino); + printf("I\-node number: %lu\en", sb.st_ino); printf("Mode: %lo (octal)\en", (unsigned long) sb.st_mode); -- 2.17.0