Understanding `@@ -1,2 +3,4 @@` part of the Git diff
diff -u <(seq 16) <(seq 16 | grep -Ev '^(2|3|14|15)$')
--- /dev/fd/11 2019-09-26 15:48:31.000000000 -0500
+++ /dev/fd/12 2019-09-26 15:48:31.000000000 -0500
@@ -1,6 +1,4 @@
1
-2
-3
4
5
6
@@ -11,6 +9,4 @@
11
12
13
-14
-15
16
-1,6means that this piece of the first file starts at line 1 and shows a total of 6 lines; therefore it shows lines 1 to 6 (-means "old", as we usually invoke it asdiff -u old new)+1,4means that this piece of the second file starts at line 1 and shows a total of 4 lines; therefore it shows lines 1 to 4 (+means "new")@@ -11,6 +9,4 @@for the second hunk is analogous: in the old file, we have 6 lines, starting at line 11 of the old file; in the new file, we have 4 lines, starting at line 9 of the new file
This is for anyone who still didn't quite understand. In
@@ -1,6 +1,4 @@pls don't read-1as "minus one" or+1as "plus one". Instead read this as "line 1 to 6" in old (first) file. Note here-implies "old" not minus.