df: Fix -k flag consistency with other BLOCKSIZE flags

This patch resolves inconsistent behavior between the -k option and other related flags, including -P. Previously, using -k resulted in output displayed in 1024-byte blocks, which did not align with the behavior of similar options such as -m and -g, where output is shown in 1M-blocks and 1G-blocks respectively.

The updated implementation ensures that -k now correctly displays sizes in 1K-blocks. In addition, the patch incorporates the POSIX requirement that when both -k -P are specified, the block size must be explicitly forced to 1024-blocks.

Together, these changes make the behavior of -k consistent, predictable, and compliant with the standard.

Signed-off-by: Ankush Mondal <[email protected]>

Author: ankushT369

bin/df/df.c

@@ -128,11 +128,12 @@ main(int argc, char *argv[])
 			/*
 			 * POSIX specifically discusses the behavior of
 			 * both -k and -P. It states that the blocksize should
-			 * be set to 1024. Thus, if this occurs, simply break
-			 * rather than clobbering the old blocksize.
+			 * be set to 1024.
 			 */
-			if (kflag)
+			if (kflag) {
+                setenv("BLOCKSIZE", "1024", 1);
 				break;
+            }
 			setenv("BLOCKSIZE", "512", 1);
 			hflag = 0;
 			break;
@@ -154,7 +155,7 @@ main(int argc, char *argv[])
 			break;
 		case 'k':
 			kflag++;
-			setenv("BLOCKSIZE", "1024", 1);
+			setenv("BLOCKSIZE", "1k", 1);
 			hflag = 0;
 			break;
 		case 'l':