I have the following files/subdirectories listed in List.txt.

$cat List.txt

FixDiff.out
Temp.txt
diff.out
dog &cat

There are no leading or trailing spaces on each line. I want to
submit this to "find" after quoting each line. This command seems to
do the quoting:

cat List.txt | sed -e 's/.*/"&"/'

It generates:

"FixDiff.out"
"Temp.txt"
"diff.out"
"dog &cat"

Here is how I fed it to the "find" command. The head command simply
ensures that I don't pollute the display with "find" output, and that
no time is wasted on the find command, thus enabling me to quickly see
the expanded command from "set -x".

set -x
find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0

Here is the output:

$ find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0

find '"' 'FixDiff.out"' '"' 'Temp.txt"' '"' 'diff.out"' '"' dog
'&cat"' -type f

$ find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0

find FixDiff.out Temp.txt diff.out dog '&cat' -type f

$ find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0

find ''\''' 'FixDiff.out'\''' ''\''' 'Temp.txt'\''' ''\'''
'diff.out'\''' ''\''' dog '&cat'\''' -type f

The 1st "find" is what I expected to work, but it generates extra
single-quotes. The 2nd "find" is a debugging step to find out exactly
what happens when the 4-line output of "cat | sed" is put onto a
single physical line for "find". Apparently, spaces are not
protected, though ampersands are. Leading quotes are protected, but
are considered separated out as distinct arguments.

The above is just a illustration of this behaviour. The actual usage
involves grepping a file instead of cat'ing it. The result is even
stranger -- using the 1st "find" above, only the 1st 2 filenames
contain quotes (wrong though they may be), while the remaining large
number of filenames have not quoting at all.

Is there a way to generate the required quoting? I realize I can
prepend backslashes to all nonstandard characters, but simply quoting
the whole thing seemed alot simpler than identifying all nonstandard
characters -- if it can be made to work.

Why do the above 3 "find" commands generate such strange quoting?

Thanks!

Mister.Fred.Ma@gmail.com wrote:
> I have the following files/subdirectories listed in List.txt.
>
> $cat List.txt
>
> FixDiff.out
> Temp.txt
> diff.out
> dog &cat
>
> There are no leading or trailing spaces on each line. I want to
> submit this to "find" after quoting each line. This command seems to
> do the quoting:
>
> cat List.txt | sed -e 's/.*/"&"/'
>
> It generates:
>
> "FixDiff.out"
> "Temp.txt"
> "diff.out"
> "dog &cat"
>
> Here is how I fed it to the "find" command. The head command simply
> ensures that I don't pollute the display with "find" output, and that
> no time is wasted on the find command, thus enabling me to quickly see
> the expanded command from "set -x".
>
> set -x
> find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
> find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
> find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>
> Here is the output:
>
> $ find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
>
> find '"' 'FixDiff.out"' '"' 'Temp.txt"' '"' 'diff.out"' '"' dog
> '&cat"' -type f
>
> $ find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
>
> find FixDiff.out Temp.txt diff.out dog '&cat' -type f
>
> $ find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>
> find ''\''' 'FixDiff.out'\''' ''\''' 'Temp.txt'\''' ''\'''
> 'diff.out'\''' ''\''' dog '&cat'\''' -type f
>
> The 1st "find" is what I expected to work, but it generates extra
> single-quotes. The 2nd "find" is a debugging step to find out exactly
> what happens when the 4-line output of "cat | sed" is put onto a
> single physical line for "find". Apparently, spaces are not
> protected, though ampersands are. Leading quotes are protected, but
> are considered separated out as distinct arguments.
>
> The above is just a illustration of this behaviour. The actual usage
> involves grepping a file instead of cat'ing it. The result is even
> stranger -- using the 1st "find" above, only the 1st 2 filenames
> contain quotes (wrong though they may be), while the remaining large
> number of filenames have not quoting at all.
>
> Is there a way to generate the required quoting? I realize I can
> prepend backslashes to all nonstandard characters, but simply quoting
> the whole thing seemed alot simpler than identifying all nonstandard
> characters -- if it can be made to work.
>
> Why do the above 3 "find" commands generate such strange quoting?
>
> Thanks!
>

The `` generates a list of IFS-separated tokens.
It is safer to read the file line by line,
and each time run a find command:

while read -r line
do
find "$line" ...
done < List.txt


--
Michael Tosch @ hp : com

On Jul 25, 6:14 pm, Michael Tosch <eed...@NO.eed.SPAM.ericsson.PLS.se>
wrote:
> Mister.Fred...@gmail.com wrote:
> > I have the following files/subdirectories listed in List.txt.
>
> > $cat List.txt
>
> > FixDiff.out
> > Temp.txt
> > diff.out
> > dog &cat
>
> > There are no leading or trailing spaces on each line. I want to
> > submit this to "find" after quoting each line. This command seems to
> > do the quoting:
>
> > cat List.txt | sed -e 's/.*/"&"/'
>
> > It generates:
>
> > "FixDiff.out"
> > "Temp.txt"
> > "diff.out"
> > "dog &cat"
>
> > Here is how I fed it to the "find" command. The head command simply
> > ensures that I don't pollute the display with "find" output, and that
> > no time is wasted on the find command, thus enabling me to quickly see
> > the expanded command from "set -x".
>
> > set -x
> > find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
> > find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
> > find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>
> > Here is the output:
>
> > $ find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
>
> > find '"' 'FixDiff.out"' '"' 'Temp.txt"' '"' 'diff.out"' '"' dog
> > '&cat"' -type f
>
> > $ find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
>
> > find FixDiff.out Temp.txt diff.out dog '&cat' -type f
>
> > $ find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>
> > find ''\''' 'FixDiff.out'\''' ''\''' 'Temp.txt'\''' ''\'''
> > 'diff.out'\''' ''\''' dog '&cat'\''' -type f
>
> > The 1st "find" is what I expected to work, but it generates extra
> > single-quotes. The 2nd "find" is a debugging step to find out exactly
> > what happens when the 4-line output of "cat | sed" is put onto a
> > single physical line for "find". Apparently, spaces are not
> > protected, though ampersands are. Leading quotes are protected, but
> > are considered separated out as distinct arguments.
>
> > The above is just a illustration of this behaviour. The actual usage
> > involves grepping a file instead of cat'ing it. The result is even
> > stranger -- using the 1st "find" above, only the 1st 2 filenames
> > contain quotes (wrong though they may be), while the remaining large
> > number of filenames have not quoting at all.
>
> > Is there a way to generate the required quoting? I realize I can
> > prepend backslashes to all nonstandard characters, but simply quoting
> > the whole thing seemed alot simpler than identifying all nonstandard
> > characters -- if it can be made to work.
>
> > Why do the above 3 "find" commands generate such strange quoting?
>
> > Thanks!
>
> The `` generates a list of IFS-separated tokens.
> It is safer to read the file line by line,
> and each time run a find command:
>
> while read -r line
> do
> find "$line" ...
> done < List.txt

Thanks, Michael. It works like a charm. I also learned that you can
pipe into a loop using "<" at the end, or using "|" at the start.

I looked up bash's "read", but I'm confused by the delimiting. It
says the IFS variable (which I assume is the default, since I didn't
change it) delimits the words in the line. The -r switch simply says
that backslashing isn't used -- not sure where that fits in, since I
don't have such a character in List.txt. It does not say that IFS is
ignored -- yet this must be what is happening, since the entire
contents of the physical line is stuffed into $line (else the find
command would report and error). So why is -r needed, and why is IFS
*apparently* not used here?

Thanks!

On Jul 25, 6:14 pm, Michael Tosch <eed...@NO.eed.SPAM.ericsson.PLS.se>
wrote:
> Mister.Fred...@gmail.com wrote:
> > I have the following files/subdirectories listed in List.txt.
>
> > $cat List.txt
>
> > FixDiff.out
> > Temp.txt
> > diff.out
> > dog &cat
>
> > There are no leading or trailing spaces on each line. I want to
> > submit this to "find" after quoting each line. This command seems to
> > do the quoting:
>
> > cat List.txt | sed -e 's/.*/"&"/'
>
> > It generates:
>
> > "FixDiff.out"
> > "Temp.txt"
> > "diff.out"
> > "dog &cat"
>
> > Here is how I fed it to the "find" command. The head command simply
> > ensures that I don't pollute the display with "find" output, and that
> > no time is wasted on the find command, thus enabling me to quickly see
> > the expanded command from "set -x".
>
> > set -x
> > find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
> > find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
> > find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>
> > Here is the output:
>
> > $ find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
>
> > find '"' 'FixDiff.out"' '"' 'Temp.txt"' '"' 'diff.out"' '"' dog
> > '&cat"' -type f
>
> > $ find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
>
> > find FixDiff.out Temp.txt diff.out dog '&cat' -type f
>
> > $ find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>
> > find ''\''' 'FixDiff.out'\''' ''\''' 'Temp.txt'\''' ''\'''
> > 'diff.out'\''' ''\''' dog '&cat'\''' -type f
>
> > The 1st "find" is what I expected to work, but it generates extra
> > single-quotes. The 2nd "find" is a debugging step to find out exactly
> > what happens when the 4-line output of "cat | sed" is put onto a
> > single physical line for "find". Apparently, spaces are not
> > protected, though ampersands are. Leading quotes are protected, but
> > are considered separated out as distinct arguments.
>
> > The above is just a illustration of this behaviour. The actual usage
> > involves grepping a file instead of cat'ing it. The result is even
> > stranger -- using the 1st "find" above, only the 1st 2 filenames
> > contain quotes (wrong though they may be), while the remaining large
> > number of filenames have not quoting at all.
>
> > Is there a way to generate the required quoting? I realize I can
> > prepend backslashes to all nonstandard characters, but simply quoting
> > the whole thing seemed alot simpler than identifying all nonstandard
> > characters -- if it can be made to work.
>
> > Why do the above 3 "find" commands generate such strange quoting?
>
> > Thanks!
>
> The `` generates a list of IFS-separated tokens.
> It is safer to read the file line by line,
> and each time run a find command:
>
> while read -r line
> do
> find "$line" ...
> done < List.txt

Thanks, Michael. It works like a charm. I also learned that you can
pipe into a loop using "<" at the end, or using "|" at the start.

I looked up bash's "read", but I'm confused by the delimiting. It
says the IFS variable (which I assume is the default, since I didn't
change it) delimits the words in the line. The -r switch simply says
that backslashing isn't used -- not sure where that fits in, since I
don't have such a character in List.txt. It does not say that IFS is
ignored -- yet this must be what is happening, since the entire
contents of the physical line is stuffed into $line (else the find
command would report and error). So why is -r needed, and why is IFS
*apparently* not used here?

Thanks!

Mister.Fred.Ma@gmail.com wrote:
> On Jul 25, 6:14 pm, Michael Tosch <eed...@NO.eed.SPAM.ericsson.PLS.se>
> wrote:
>> Mister.Fred...@gmail.com wrote:
>>> I have the following files/subdirectories listed in List.txt.
>>> $cat List.txt
>>> FixDiff.out
>>> Temp.txt
>>> diff.out
>>> dog &cat
>>> There are no leading or trailing spaces on each line. I want to
>>> submit this to "find" after quoting each line. This command seems to
>>> do the quoting:
>>> cat List.txt | sed -e 's/.*/"&"/'
>>> It generates:
>>> "FixDiff.out"
>>> "Temp.txt"
>>> "diff.out"
>>> "dog &cat"
>>> Here is how I fed it to the "find" command. The head command simply
>>> ensures that I don't pollute the display with "find" output, and that
>>> no time is wasted on the find command, thus enabling me to quickly see
>>> the expanded command from "set -x".
>>> set -x
>>> find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
>>> find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
>>> find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>>> Here is the output:
>>> $ find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
>>> find '"' 'FixDiff.out"' '"' 'Temp.txt"' '"' 'diff.out"' '"' dog
>>> '&cat"' -type f
>>> $ find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
>>> find FixDiff.out Temp.txt diff.out dog '&cat' -type f
>>> $ find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
>>> find ''\''' 'FixDiff.out'\''' ''\''' 'Temp.txt'\''' ''\'''
>>> 'diff.out'\''' ''\''' dog '&cat'\''' -type f
>>> The 1st "find" is what I expected to work, but it generates extra
>>> single-quotes. The 2nd "find" is a debugging step to find out exactly
>>> what happens when the 4-line output of "cat | sed" is put onto a
>>> single physical line for "find". Apparently, spaces are not
>>> protected, though ampersands are. Leading quotes are protected, but
>>> are considered separated out as distinct arguments.
>>> The above is just a illustration of this behaviour. The actual usage
>>> involves grepping a file instead of cat'ing it. The result is even
>>> stranger -- using the 1st "find" above, only the 1st 2 filenames
>>> contain quotes (wrong though they may be), while the remaining large
>>> number of filenames have not quoting at all.
>>> Is there a way to generate the required quoting? I realize I can
>>> prepend backslashes to all nonstandard characters, but simply quoting
>>> the whole thing seemed alot simpler than identifying all nonstandard
>>> characters -- if it can be made to work.
>>> Why do the above 3 "find" commands generate such strange quoting?
>>> Thanks!
>> The `` generates a list of IFS-separated tokens.
>> It is safer to read the file line by line,
>> and each time run a find command:
>>
>> while read -r line
>> do
>> find "$line" ...
>> done < List.txt
>
> Thanks, Michael. It works like a charm. I also learned that you can
> pipe into a loop using "<" at the end, or using "|" at the start.
>
> I looked up bash's "read", but I'm confused by the delimiting. It
> says the IFS variable (which I assume is the default, since I didn't
> change it) delimits the words in the line. The -r switch simply says
> that backslashing isn't used -- not sure where that fits in, since I
> don't have such a character in List.txt. It does not say that IFS is
> ignored -- yet this must be what is happening, since the entire
> contents of the physical line is stuffed into $line (else the find
> command would report and error). So why is -r needed, and why is IFS
> *apparently* not used here?
>

In case List.txt has

line\
1

a normal read would compose that to "line1", therefore the -r

IFS is used to split the line:

while read -r word1 word2 rest

But we read the entire line.


--
Michael Tosch @ hp : com

On Jul 25, 7:24 pm, Michael Tosch <eed...@NO.eed.SPAM.ericsson.PLS.se>
wrote:
> Mister.Fred...@gmail.com wrote:
> > On Jul 25, 6:14 pm, Michael Tosch <eed...@NO.eed.SPAM.ericsson.PLS.se>
> > wrote:
> >> Mister.Fred...@gmail.com wrote:
> >>> I have the following files/subdirectories listed in List.txt.
> >>> $cat List.txt
> >>> FixDiff.out
> >>> Temp.txt
> >>> diff.out
> >>> dog &cat
> >>> There are no leading or trailing spaces on each line. I want to
> >>> submit this to "find" after quoting each line. This command seems to
> >>> do the quoting:
> >>> cat List.txt | sed -e 's/.*/"&"/'
> >>> It generates:
> >>> "FixDiff.out"
> >>> "Temp.txt"
> >>> "diff.out"
> >>> "dog &cat"
> >>> Here is how I fed it to the "find" command. The head command simply
> >>> ensures that I don't pollute the display with "find" output, and that
> >>> no time is wasted on the find command, thus enabling me to quickly see
> >>> the expanded command from "set -x".
> >>> set -x
> >>> find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
> >>> find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
> >>> find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
> >>> Here is the output:
> >>> $ find ` cat List.txt | sed -e 's/.*/"&"/' ` -type f 2>&1 | head -n 0
> >>> find '"' 'FixDiff.out"' '"' 'Temp.txt"' '"' 'diff.out"' '"' dog
> >>> '&cat"' -type f
> >>> $ find ` cat List.txt | sed -e 's/.*/&/' ` -type f 2>&1 | head -n 0
> >>> find FixDiff.out Temp.txt diff.out dog '&cat' -type f
> >>> $ find ` cat List.txt | sed -e "s/.*/'&'/" ` -type f 2>&1 | head -n 0
> >>> find ''\''' 'FixDiff.out'\''' ''\''' 'Temp.txt'\''' ''\'''
> >>> 'diff.out'\''' ''\''' dog '&cat'\''' -type f
> >>> The 1st "find" is what I expected to work, but it generates extra
> >>> single-quotes. The 2nd "find" is a debugging step to find out exactly
> >>> what happens when the 4-line output of "cat | sed" is put onto a
> >>> single physical line for "find". Apparently, spaces are not
> >>> protected, though ampersands are. Leading quotes are protected, but
> >>> are considered separated out as distinct arguments.
> >>> The above is just a illustration of this behaviour. The actual usage
> >>> involves grepping a file instead of cat'ing it. The result is even
> >>> stranger -- using the 1st "find" above, only the 1st 2 filenames
> >>> contain quotes (wrong though they may be), while the remaining large
> >>> number of filenames have not quoting at all.
> >>> Is there a way to generate the required quoting? I realize I can
> >>> prepend backslashes to all nonstandard characters, but simply quoting
> >>> the whole thing seemed alot simpler than identifying all nonstandard
> >>> characters -- if it can be made to work.
> >>> Why do the above 3 "find" commands generate such strange quoting?
> >>> Thanks!
> >> The `` generates a list of IFS-separated tokens.
> >> It is safer to read the file line by line,
> >> and each time run a find command:
>
> >> while read -r line
> >> do
> >> find "$line" ...
> >> done < List.txt
>
> > Thanks, Michael. It works like a charm. I also learned that you can
> > pipe into a loop using "<" at the end, or using "|" at the start.
>
> > I looked up bash's "read", but I'm confused by the delimiting. It
> > says the IFS variable (which I assume is the default, since I didn't
> > change it) delimits the words in the line. The -r switch simply says
> > that backslashing isn't used -- not sure where that fits in, since I
> > don't have such a character in List.txt. It does not say that IFS is
> > ignored -- yet this must be what is happening, since the entire
> > contents of the physical line is stuffed into $line (else the find
> > command would report and error). So why is -r needed, and why is IFS
> > *apparently* not used here?
>
> In case List.txt has
>
> line\
> 1
>
> a normal read would compose that to "line1", therefore the -r
>
> IFS is used to split the line:
>
> while read -r word1 word2 rest
>
> But we read the entire line.

Thanks, Michael.

Fred