According to the manual: (I) Typing the suspend character (typically ^Z, Control-Z) while a process is running causes that process to be stopped and returns control to bash.
(II) An OR list has the form command1 || command2 command2 is executed if and only if command1 returns a non-zero exit status. The return status of AND and OR lists is the exit status of the last command executed in the list. In the following example: esoriano@omac:~$ sleep 10 || echo hey ^Z [5]+ Stopped sleep 10 hey esoriano@omac:~$ there are two different issues: (I) echo is executed when sleep is suspended, i.e., command2 is executed before command1 exits. (II) the exit status of command1 (when the job is resumed) will be 0 and command2 is (was) executed. 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='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I../. -I.././include -I.././lib -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -fdebug-prefix-map=/build/bash-vEMnMR/bash-4.4.18=. -fstack-protector-strong -Wformat -Werror=format-security -Wall -Wno-parentheses -Wno-format-security uname output: Linux omac 4.15.0-34-generic #37-Ubuntu SMP Mon Aug 27 15:21:48 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux Machine Type: x86_64-pc-linux-gnu Bash Version: 4.4 Patch Level: 19 Release Status: release Description: [Detailed description of the problem, suggestion, or complaint.] Repeat-By: [Describe the sequence of events that causes the problem to occur.] Fix: [Description of how to fix the problem. If you don't know a fix for the problem, don't include this section.]