[PATCH] format_proc_swaps: ensure space between fields for clarity

[Brian Inglis]

page/swap space name >= 40 or size/used >= 8 leaves no space between fields;
ensure a space after name and add extra tabs after size and used fields;
output appears like Linux 5.8 after changes to mm/swapfile(swap_show);

proc-swaps-space-before.log:
==> /proc/swaps <==
Filename				Type		Size	Used	Priority
/mnt/c/pagefile.sys                     file            11567748292920  0
/mnt/d/pagefile.sys                     file            12582912205960  0

proc-swaps-space-after.log:
==> /proc/swaps <==
Filename				Type		Size		Used		Priority
/mnt/c/pagefile.sys			file		11567748	241024		0
/mnt/d/pagefile.sys			file		12582912	182928		0
---
 winsup/cygwin/fhandler_proc.cc | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/winsup/cygwin/fhandler_proc.cc b/winsup/cygwin/fhandler_proc.cc
index 7cd0b3af02..eb4efb07d4 100644
--- a/winsup/cygwin/fhandler_proc.cc
+++ b/winsup/cygwin/fhandler_proc.cc
@@ -1920,7 +1920,7 @@ format_proc_swaps (void *, char *&destbuf)
     }
 
   bufptr += __small_sprintf (bufptr,
-			     "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
+			"Filename\t\t\t\tType\t\tSize\t\tUsed\t\tPriority\n");
 
   if (spi && NT_SUCCESS (status))
     {
@@ -1932,8 +1932,17 @@ format_proc_swaps (void *, char *&destbuf)
 	  used = (unsigned long long) spp->TotalUsed * wincap.page_size ();
 	  cygwin_conv_path (CCP_WIN_W_TO_POSIX, spp->FileName.Buffer,
 			    filename, NT_MAX_PATH);
-	  bufptr += sprintf (bufptr, "%-40s%-16s%-8llu%-8llu%-8d\n",
-			     filename, "file", total >> 10, used >> 10, 0);
+	  /* ensure space between fields for clarity */
+	  size_t tabo = strlen (filename) / 8;	/* offset tabs to space name */
+	  bufptr += sprintf (bufptr, "%s%s%s\t\t%llu%s\t%llu%s\t%d\n",
+				    filename,
+				    tabo < 5 ? "\t\t\t\t\t" + tabo : " ",
+					"file",
+					    total >> 10,
+					    total < 10000000000 ? "\t" : "",
+						used  >> 10,
+						used  < 10000000000 ? "\t" : "",
+								0);
 	}
       while (spp->NextEntryOffset
 	     && (spp = (PSYSTEM_PAGEFILE_INFORMATION)
-- 
2.31.1