Hi, This bug report has been my first one for Bash. I have not found how to check the status of the bug. Would you please provide this information?
Below are a couple more issues I found. There is an inconsistency with the documentation and behavior of the ^ word designator. According to documentation, it refers to the first argument but does not require a ':' before it if it starts the word designator. However, it does not act like the numerical word designator 1 at the end of a range. [root@localhost ~]# echo a b c a b c [root@localhost ~]# echo !!:1-1 echo a a [root@localhost ~]# echo a b c a b c [root@localhost ~]# echo !!:^-^ echo a b^ a b^ Also it is not explicitly documented that :- is equivalent to :0- [root@localhost ~]# echo a b c d a b c d [root@localhost ~]# echo !!:- echo echo a b c echo a b c [root@localhost ~]# echo a b c d a b c d [root@localhost ~]# echo !!:0- echo echo a b c echo a b c Jim Monte On Thu, Oct 3, 2019 at 6:19 PM Jim Monte <jim.mont...@gmail.com> wrote: > Hi All, > > Below are some issues I found with history substitution. I am duplicating > its behavior in a somewhat different use, and found issues with the > documentation and bugs as described. > > Jim Monte > > > > > From: jim > To: bug-bash@gnu.org > Subject: Issues with history substitution and its documentation > > Configuration Information [Automatically generated, do not change]: > Machine: x86_64 > OS: linux-gnu > Compiler: gcc > Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' > -DCONF_OSTYPE='l$ > uname output: Linux T5500-Ubuntu 4.18.0-22-generic #23~18.04.1-Ubuntu SMP > Thu J$ > Machine Type: x86_64-pc-linux-gnu > > Bash Version: 4.4 > Patch Level: 19 > Release Status: release > > Description: > > ============================================================================= > Documentation of quick substitution is incorrect (or does not match > behavior). > > I believe this issue is an error with the documentation of history > "Quick Substitution" that has existed since the first snapshot available at > web.archive.org in 2007 at > > > https://web.archive.org/web/20071223174140/http://www.gnu.org/software/bash/manual/html_node/Event-Designators.html > > At the least it is true that bash does not behave as the documentation > states, > but it does act in a way that is more reasonable (to me) than what is > written. > > The documentation states that ^string1^string2^ is equivalent to > !!:s/string1/string2/. However, bash treats it as equivalent to > !!:s^string1^string2^. > > jim@T5500-Ubuntu:~$ echo /a > /a > jim@T5500-Ubuntu:~$ ^/a^b^ > echo b > b > jim@T5500-Ubuntu:~$ echo /a > /a > jim@T5500-Ubuntu:~$ !!:s//a/b/ > echo ab/ > ab/ > jim@T5500-Ubuntu:~$ echo /a > /a > jim@T5500-Ubuntu:~$ !!:s^/a^b^ > echo b > b > > > ============================================================================= > Behavior of empty "old" string in a substitution is undefined. > > The earlier example also shows a related but different issue with the > !!:s//a/b/ command, where the string to locate is empty. > It causes /a to be replaced by a and the b/ is appended. > > But > jim@T5500-Ubuntu:~$ echo ///a > ///a > jim@T5500-Ubuntu:~$ !!:s//z/ > echo //z > //z > > Here the empty string caused /a to be replaced by z. > > However, > jim@T5500-Ubuntu:~$ echo ///abcdefg > ///abcdefg > jim@T5500-Ubuntu:~$ !!:s//z/ > echo //zbcdefg > //zbcdefg > > Here a slash and the first character of the second word are replaced by z. > > > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:s//z/ > echo z b c > z b c > > > jim@T5500-Ubuntu:~$ echo /// > /// > jim@T5500-Ubuntu:~$ !!:s//z/ > bash: :s//z/: substitution failed > > Using :gs instead of :s does not change the results. > > > ============================================================================= > BUG > If an event designator has a leading - character, it is ignored. > > jim@T5500-Ubuntu:~/tmp$ cat main.c > #include <stdio.h> > int main(void) > { > (void) fprintf(stdout, "Hello, world!\n"); > return 0; > } > > jim@T5500-Ubuntu:~/tmp$ gcc main.c -o"-a" > jim@T5500-Ubuntu:~/tmp$ gcc main.c -o"-b" > jim@T5500-Ubuntu:~/tmp$ -a > Hello, world! > jim@T5500-Ubuntu:~/tmp$ !-a:s/a/b > bpt-cache abc > > > > ============================================================================= > Documentation of the :h and :t modifiers in section 9.3.3 is incomplete. > :h removes the last / and everything after it if a / is present. Otherwise > it does nothing. > > :t removes everything before and including the last / if one is present. > Otherwise it does nothing. > > If a slash is present, !!:h/!!:t is equivalent to !!. > > jim@T5500-Ubuntu:~$ echo /a/b/c/d > /a/b/c/d > jim@T5500-Ubuntu:~$ !!:h > echo /a/b/c > /a/b/c > jim@T5500-Ubuntu:~$ echo /a/b/c/d > /a/b/c/d > jim@T5500-Ubuntu:~$ !!:h:h > echo /a/b > /a/b > jim@T5500-Ubuntu:~$ echo /a/b/c/d > /a/b/c/d > jim@T5500-Ubuntu:~$ !!:h:h:h > echo /a > /a > jim@T5500-Ubuntu:~$ echo /a/b/c/d > /a/b/c/d > jim@T5500-Ubuntu:~$ !!:h:h:h:h > echo > > jim@T5500-Ubuntu:~$ > jim@T5500-Ubuntu:~$ echo /a/b/c/d > /a/b/c/d > jim@T5500-Ubuntu:~$ !!:t > d > d: command not found > > > jim@T5500-Ubuntu:~$ echo a/b > a/b > jim@T5500-Ubuntu:~$ !!:h/!!:t > echo a/b > a/b > jim@T5500-Ubuntu:~$ echo a/b > a/b > jim@T5500-Ubuntu:~$ !! > echo a/b > a/b > > > > ============================================================================= > Documentation of the :r and :e modifiers is incomplete. > :r removes the last ".suffix" and everything after it, if a ".suffix" is > present. Otherwise it does nothing. > :e leaves the last ".suffix" and everything after it, if a ".suffix" is > present. Otherwise it does nothing. > > jim@T5500-Ubuntu:~$ echo .suffix a b .suffix c d > .suffix a b .suffix c d > jim@T5500-Ubuntu:~$ !!:r > echo .suffix a b > .suffix a b > jim@T5500-Ubuntu:~$ echo .suffix a b .suffix c d > .suffix a b .suffix c d > jim@T5500-Ubuntu:~$ !!:r:r > echo > > jim@T5500-Ubuntu:~$ echo .suffix a b .suffix c d > .suffix a b .suffix c d > jim@T5500-Ubuntu:~$ !!:e > .suffix c d > > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:r > echo a b c > a b c > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:e > echo a b c > a b c > > > ============================================================================= > BUG > :p does not suppress execution if it is duplicated. > > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:p > echo a b c > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:p:p > echo a b c > a b c > > > ============================================================================= > Documentation of :q and :x is incomplete. > If :q and :x are repeated, the last specification is taken. > > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:q > 'echo a b c' > echo a b c: command not found > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:x > 'echo' 'a' 'b' 'c' > a b c > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:q:x > 'echo' 'a' 'b' 'c' > a b c > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:q:x:q > 'echo a b c' > echo a b c: command not found > jim@T5500-Ubuntu:~$ echo a b c > a b c > jim@T5500-Ubuntu:~$ !!:q:x:q:x > 'echo' 'a' 'b' 'c' > a b c > > > ============================================================================= > Finally, documentation of G should mention that it can be used with both > :s and &. > > >
