History Expansion in Arithmetic Expansion
Configuration Information [Automatically generated, do not change]: Machine: aarch64 OS: linux-gnu Compiler: gcc Compilation CFLAGS: -march=armv8-a -O2 -pipe -fstack-protector-strong -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/local/bin:/usr/bin' -DSTANDARD_UTILS_PATH='/usr/bin' -DSYS_BASHRC='/etc/bash.bashrc' -DSYS_BASH_LOGOUT='/etc/bash.bash_logout' -DNON_INTERACTIVE_LOGIN_SHELLS uname output: Linux localhost 4.14.116 #1 SMP PREEMPT Tue Mar 22 15:13:10 CST 2022 aarch64 GNU/Linux Machine Type: aarch64-unknown-linux-gnu Bash Version: 5.2 Patch Level: 26 Release Status: release Description: I am unable to use logical inversion operators in line arithmetic extensions, nor can I escape them, which is undoubtedly abnormal Repeat-By: ```bash $ ((!RANDOM)) bash: !RANDOM: event not found ```
Re: History Expansion in Arithmetic Expansion
On Sat, Mar 23, 2024, 16:34 A4-Tacks wrote: > Configuration Information [Automatically generated, do not change]: > Machine: aarch64 > OS: linux-gnu > Compiler: gcc > Compilation CFLAGS: -march=armv8-a -O2 -pipe -fstack-protector-strong > -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat > -Werror=format-security -fstack-clash-protection > -DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/local/bin:/usr/bin' > -DSTANDARD_UTILS_PATH='/usr/bin' -DSYS_BASHRC='/etc/bash.bashrc' > -DSYS_BASH_LOGOUT='/etc/bash.bash_logout' -DNON_INTERACTIVE_LOGIN_SHELLS > uname output: Linux localhost 4.14.116 #1 SMP PREEMPT Tue Mar 22 15:13:10 > CST 2022 aarch64 GNU/Linux > Machine Type: aarch64-unknown-linux-gnu > > Bash Version: 5.2 > Patch Level: 26 > Release Status: release > > Description: > I am unable to use logical inversion operators in line > arithmetic extensions, nor can I escape them, which is undoubtedly > abnormal > > Repeat-By: > ```bash > $ ((!RANDOM)) > bash: !RANDOM: event not found > ``` > small workaround (( ! bla )) >
Re: History Expansion in Arithmetic Expansion
Thank you, this is very effective! Replied Message | From | alex xmb sw ratchev | | Date | 03/23/2024 23:38 | | To | A4-Tacks | | Cc | bug-bash | | Subject | Re: History Expansion in Arithmetic Expansion | On Sat, Mar 23, 2024, 16:34 A4-Tacks wrote: Configuration Information [Automatically generated, do not change]: Machine: aarch64 OS: linux-gnu Compiler: gcc Compilation CFLAGS: -march=armv8-a -O2 -pipe -fstack-protector-strong -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/local/bin:/usr/bin' -DSTANDARD_UTILS_PATH='/usr/bin' -DSYS_BASHRC='/etc/bash.bashrc' -DSYS_BASH_LOGOUT='/etc/bash.bash_logout' -DNON_INTERACTIVE_LOGIN_SHELLS uname output: Linux localhost 4.14.116 #1 SMP PREEMPT Tue Mar 22 15:13:10 CST 2022 aarch64 GNU/Linux Machine Type: aarch64-unknown-linux-gnu Bash Version: 5.2 Patch Level: 26 Release Status: release Description: I am unable to use logical inversion operators in line arithmetic extensions, nor can I escape them, which is undoubtedly abnormal Repeat-By: ```bash $ ((!RANDOM)) bash: !RANDOM: event not found ``` small workaround (( ! bla ))
Re: History Expansion in Arithmetic Expansion
On Sat, Mar 23, 2024, at 11:34 AM, A4-Tacks wrote:
> Description:
> I am unable to use logical inversion operators in line
> arithmetic extensions, nor can I escape them, which is undoubtedly
> abnormal
>
> Repeat-By:
> ```bash
> $ ((!RANDOM))
> bash: !RANDOM: event not found
> ```
Unfortunately this is intentional and documented. In interactive
shells with default settings, unquoted `!' introduces a history
expansion [1]. You cannot backslash-escape `!' within `((exp))'
because `exp' is treated almost [*] as if it were double-quoted,
and within double quotes `\' escapes `!' but is not removed [3].
[1]: https://www.gnu.org/software/bash/manual/html_node/History-Interaction.html
[2]:
https://www.gnu.org/software/bash/manual/html_node/Conditional-Constructs.html
[3]: https://www.gnu.org/software/bash/manual/html_node/Double-Quotes.html
[*]: One exception is that double quotes themselves are removed,
so another (arguably worse) workaround is `(("!"RANDOM))'.
--
vq
Add option to just print history, with no added timestamps or line numbers
$ help history should mention how in the world one is supposed to just print the plain history, without any line numbers or time stamps. You might say, "Just strip it off with perl or sed." Well, fine. Then mention that in help history. Currently one needs massive superfund environmental clean-up effort workarounds, e.g., $ HISTTIMEFORMAT=' ' history | perl -pwle 's/^\s+\S+\s+//' Better yet, add a history -j: Just print history, with no added timestamps or line numbers, etc. Or OK, there's HISTTIMEFORMAT. How about also a HISTFORMAT (default " %5n %t %h\n" or whatever,) so one could use "%h\n" for "just give me the history item."
Re: Add option to just print history, with no added timestamps or line numbers
On Sun, Mar 24, 2024, at 1:40 AM, Dan Jacobson wrote: > $ help history > should mention how in the world one is supposed to just print the plain > history, > without any line numbers or time stamps. fc -ln 1 -- vq
