[SOLVED] To enclose a string with quote pair (or its double) in a bigger string

BudiKusasi · 12-22-2020, 03:35 AM

How to enclose a string with quote pair, or its double, in a bigger string from the Bash expansion ?

Code:

u=`echo fo* b* fo*b`
echo $u

$ foo bar foobar foo bar
the last is supposed to be a space contained string enclosed with quote pair, or its double, so

$ foo bar foobar 'foo bar'

i.e

Quote:

u="foo bar foobar 'foo bar'"

Thanks before

pan64 · 12-22-2020, 04:07 AM

There are several problems:
1. do not use backick and echo

Code:

#wrong
u=`echo fo* b* fo*b`
#good
u="fo* b* fo*b"
# or probably something else, but it depends on the globbing [if you want].

2. echo $u is misleading

Code:

u="sdff  asd                 dsaf"
echo $u
sdff asd dsaf
echo "$u"
sdff  asd                 dsaf

the variable without " will not be protected and bash will evaluate the line before executing that echo (and whitespace will be collapsed).

finally I think you need arrays, something like this:

Code:

u=( fo* b* fo*b )
echo ${u[0]}
foo
echo ${u[3]}
foo bar

relying on the bash command line interpreter is not a good idea anyway. But anyway, we need to know more to give better help...

shruggy · 12-22-2020, 04:33 AM

Another possibility

Code:

$ tree
── a b
    ├── a`b'c
    ├── a blank -> a space
    ├── a,comma
    ├── a\012newline
    ├── a|pipe
    ├── a space
    ├── dah -> examples
    ├── d e
    ├── `def'
    ├── dir\012newline
    ├── examples
    │   ├── f1
    │   ├── f2
    │   ├── top-1m.csv
    │   └── top-1m.csv.zip
    ├── g"h
    └── --help

6 directories, 12 files
$ printf -v x "%q\n" a*/a*;echo "$x"
a\ b/a\`b\'c
a\ b/a\ blank
a\ b/a\,comma
$'a b/a\nnewline'
a\ b/a\|pipe
a\ b/a\ space

BudiKusasi · 12-22-2020, 04:52 AM

Quote:

Originally Posted by shruggy

Another possibility

Code:

$ tree
── a b
    ├── a`b'c
    ├── a blank -> a space
    ├── a,comma
    ├── a\012newline
    ├── a|pipe
    ├── a space
    ├── dah -> examples
    ├── d e
    ├── `def'
    ├── dir\012newline
    ├── examples
    │   ├── f1
    │   ├── f2
    │   ├── top-1m.csv
    │   └── top-1m.csv.zip
    ├── g"h
    └── --help

6 directories, 12 files
$ printf -v x "%q\n" a*/a*;echo "$x"
a\ b/a\`b\'c
a\ b/a\ blank
a\ b/a\,comma
$'a b/a\nnewline'
a\ b/a\|pipe
a\ b/a\ space

Thanks for the excellence!

MadeInGermany · 12-23-2020, 05:06 AM

Get used to newline separators:

Code:

u=$(printf "%s\n" fo* b* fo*b)

Now

Code:

echo "$u"

will show the filenames with embedded space characters.

If you want to field-split on newlines only, consider setting IFS

Code:

oIFS=$IFS
IFS="
"
# split on IFS into a word list
for word in $u
do
  echo "$word"
done
# split on IFS into an array
array=($u)
printf "%s\n" "${array[@]}"
# restore IFS
IFS=$oIFS

Note that the zsh does not field-split a $var, needs $=var