[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[bug-diffutils] bug#55652: please elaborate on diff -u -I RE
From: |
Harald Dunkel |
Subject: |
[bug-diffutils] bug#55652: please elaborate on diff -u -I RE |
Date: |
Thu, 26 May 2022 11:15:39 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 |
Hi folks,
I have hoped that
diff -I '^[[:space:]]*\#' file1 file2
would ignore comment lines, but it doesn't work as I expected.
Example:
#!/bin/bash
diff -version | head -1
echo -e '\t# comment 1' >/tmp/x1
echo -e '\t# comment 2' >/tmp/x2
diff -u -I '^[[:space:]]*\#' /tmp/x1 /tmp/x2 && echo 'no diffs'
echo -e '' >>/tmp/x1
echo -e '' >>/tmp/x2
diff -u -I '^[[:space:]]*\#' /tmp/x1 /tmp/x2 && echo 'still no diffs'
echo -e 'hello, world' >>/tmp/x2
diff -u -I '^[[:space:]]*\#' /tmp/x1 /tmp/x2 && echo 'no diffs'
echo "diff --normal"
diff -I '^[[:space:]]*\#' /tmp/x1 /tmp/x2 && echo 'no diffs'
Output:
diff (GNU diffutils) 3.8
no diffs
still no diffs
--- /tmp/x1 2022-05-26 10:54:36.187361365 +0200
+++ /tmp/x2 2022-05-26 10:54:36.191361276 +0200
@@ -1,2 +1,3 @@
- # comment 1
+ # comment 2
+hello, world
diff --normal
2a3
> hello, world
This seems weird. Only 1 line has been appended to x2 before running
diff the third time. It does not match the pattern. How comes diff -u
reports 2 different lines, with an unchanged line in between? Is this
as expected?
Regards
Harri
- [bug-diffutils] bug#55652: please elaborate on diff -u -I RE,
Harald Dunkel <=