On Fri, 8 Jul 2022 13:22:46 +0300
Oğuz <oguzismailuy...@gmail.com> wrote:
> 8 Temmuz 2022 Cuma tarihinde Yair Lenga <yair.le...@gmail.com> yazdı:
> >
> > Practical Example - real life. A job has to copy 3 critical data files. It
> > then sends notification via email (non-critical).
> >
> > #! /bin/bash
> > set -o errfail
> > function copy-files {
> > # ALL files are critical, script will not cont
> > cp /new/file1 /production/path/
> > cp /new/file2 /production/path/
> > # Use the files for something - e.g., count the lines.
> > important-job /production/path/file1 /production/path/file2
> >
> > ls -l /production/path | mail -s "all-good" not...@company.com ||
> > true # Not critical
> > }
> >
> > if copy-files ; then
> > more-critical-jobs
> > echo "ALL GOOD"
> > else
> > mail -s "PROBLEM" nor...@company.com < /dev/null
> > fi
> >
> > What is the difference ? consider the case where /new/file1 does not
> > exists, which is critical error.
> > * Without errfail, an error message will be sent to script stderr, but the
> > script will continue to copy the 2nd file, and to perform the
> > important-job, even though the data is not ready.
>
>
> How is this any better than doing `cp ... && cp ... && important-job ...'?
Just to elaborate on the premise of the question, rather than address the
question itself, the sample could have been written as:
#!/bin/bash
copy_files() {
cp /new/file1 /production/path/ &&
cp /new/file2 /production/path/ &&
important-job /production/path/file1 /production/path/file2
}
if copy_files; then
ls -l /production/path | mail -s "all-good" not...@company.com
echo "ALL GOOD"
else
mail -s "PROBLEM" not...@company.com < /dev/null
false # not in the original but one probably wanted either this or exit
1
fi
Alternatively, if it is considered necessary to issue ls from within the
function:
copy_files() {
cp /new/file1 /production/path/ &&
cp /new/file2 /production/path/ &&
important-job /production/path/file1 /production/path/file2 || return
ls -l /production/path | mail -s "all-good" not...@company.com
true
}
Ultimately, which approach is easier to reason with? Consider it as an open
question.
--
Kerin Millar
