Bash expansion


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# 1  
Bash expansion

Hello.
I cannot write a command without using eval.
Any help is welcome

Note 1 : What does the function SOMETHING has no importance.
Note 2 : What does the command find has no importance.

It is an expansion variable problem : where to put ["] or [\"] or [ '] or anythings else

What works (FILTRE_1 and FILTRE_2 are taken into account) :

Code:
function CHERCHE () {

    MY_PATH1="$1"
    if [[  ! -d "$MY_PATH1" ]] ; then
        echo "doing : $MY_PATH1"
        /usr/bin/kate "$MY_PATH1"
    fi
}
export -f CHERCHE

MY_PATH="/home/bidon"

FILTRE_1=" -path  $MY_PATH/.local/share/kscreen  -o -path  $MY_PATH/.local/share/baloo   -o -path  $MY_PATH/.dbus"

FILTRE_2=" ! -name \".direct*\"  ! -name \".Xauthority\"  ! -name \".xsession*\"  ! -name \".bash_history\" "

CMD="find \"$MY_PATH\"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_2 -exec bash -c 'CHERCHE \$0 '  {} \; \)  "
echo "COMMAND : $CMD"
eval "$CMD"

# The command return 9 files which is the good result

What does not works (FILTRE_1 is taken into account, FILTRE_2 or FILTRE_3 or FILTRE_2 is ignored ) :
Filter_2 is same as above

Code:
FILTRE_2=" ! -name \".direct*\"  ! -name \".Xauthority\"  ! -name \".xsession*\"  ! -name \".bash_history\" "

FILTRE_3=' ! -name ".direct*"  ! -name ".Xauthority"  ! -name ".xsession*"  ! -name ".bash_history" '

FILTRE_4=" ! -name '.direct*'  ! -name '.Xauthority' ! -name '.xsession*'  ! -name '.bash_history' "

find "$MY_PATH"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_2 -exec bash -c 'CHERCHE "$0" ' {} \;  \)
#FILTER_2 does nothing

find "$MY_PATH"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_3 -exec bash -c 'CHERCHE "$0" ' {} \;  \)
#FILTER_3 does nothing

find "$MY_PATH"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_4 -exec bash -c 'CHERCHE "$0" ' {} \;  \)
#FILTER_4 does nothing

#Each command return 15 files because filter 3,4,5 , does nothing.

# 2  
Not clear. What is the problem?
- Do you want to eliminate eval?
- Does the overall logics not deliver what you need? Please be aware that a chain -o (OR operators) stops after the first to evaluate to TRUE.
- How are the two code snippets in above related? What and/or where is filter 5?
- Why does filter 2 work in the first snippet but doesn't in the second.
# 3  
I believe you don't need any quotes around the -name parameters as shell will expand the variables into a single argument anyway for example:

Code:
$ MY_PATH=/tmp/jcdole
$ mkdir -p $MY_PATH/{test,.local/share/{kscreen,ballo},.dbus}/{test{1,2},.direct{A,B,C},.Xauthority,.xsession1,.bash_history}
$ F1="  -path  $MY_PATH/.local/share/kscreen  -o -path  $MY_PATH/.local/share/ballo   -o -path  $MY_PATH/.dbus "
$ F2=" ! -name .direct*  ! -name .Xauthority  ! -name .xsession*  ! -name .bash_history "
$ find "$MY_PATH" -type d \( $F1 \)  -prune -o \( $F2 -print \)
/tmp/jcdole
/tmp/jcdole/.local
/tmp/jcdole/.local/share
/tmp/jcdole/test
/tmp/jcdole/test/test1
/tmp/jcdole/test/test2


Without 2nd Filter you get:

Code:
$ $ find "$MY_PATH" -type d \( $F1 \)  -prune -o -print
/tmp/jcdole
/tmp/jcdole/.local
/tmp/jcdole/.local/share
/tmp/jcdole/test
/tmp/jcdole/test/.bash_history
/tmp/jcdole/test/.directA
/tmp/jcdole/test/.directB
/tmp/jcdole/test/.directC
/tmp/jcdole/test/.Xauthority
/tmp/jcdole/test/.xsession1
/tmp/jcdole/test/test1
/tmp/jcdole/test/test2


Last edited by Chubler_XL; 02-09-2017 at 05:59 PM.. Reason: Added output without the 2nd filter
# 4  
Additional: if $MY_PATH has the potential to contain whitespace it gets a little more tricky. After some mucking around I did find this solution in bash using arrays:

Code:
$ MY_PATH=/tmp/jc\ dole
$ mkdir -p "$MY_PATH"/{test,.local/share/{kscreen,ballo},.dbus}/{test{1,2},.direct{A,B,C},.Xauthority,.xsession1,.bash_history}
$ F1=( -path "$MY_PATH"/.local/share/kscreen -o -path "$MY_PATH"/.local/share/ballo -o -path "$MY_PATH"/.dbus )
$ set -f
$ F2=(! -name .direct*  ! -name .Xauthority  ! -name .xsession*  ! -name .bash_history)
$ OLDIFS=$IFS
$ IFS=
$ find "$MY_PATH"  -type d \( ${F1[*]} \)  -prune -o \( ${F2[*]} -print \)
/tmp/jc dole
/tmp/jc dole/.local
/tmp/jc dole/.local/share
/tmp/jc dole/test
/tmp/jc dole/test/test1
/tmp/jc dole/test/test2
$ IFS=$OLDIFS
$ set +f

Note: set -f is required to stop glob expansion of wildcards within the F2 array as we want to pass the wildcards onto find

Last edited by Chubler_XL; 02-10-2017 at 05:48 AM..
# 5  
Given that there is no way to know what files might be present in the directory in which this script might be run, to guarantee that you won't get a syntax error in find if .direct* or .xsession* expand to more than one filename, and to guarantee that all files with the desired names will be matched if either of those patterns match a single filename in the current directory, I think it would be safer to change:
Code:
F2=(! -name .direct*  ! -name .Xauthority  ! -name .xsession*  ! -name .bash_history -print)

in the code Chubler_XL suggested in post #4 to:
Code:
F2=(! -name '.direct*'  ! -name .Xauthority  ! -name '.xsession*'  ! -name .bash_history -print)

(quoting those two filename matching patterns).
# 6  
Quote:
Originally Posted by RudiC
Not clear. What is the problem?
>- Do you want to eliminate eval?

yes.
I use { CMD="..." /// echo "$CMD" /// eval "$CMD" } when debuging scripts.

>- Does the overall logics not deliver what you need? Please be aware that a chain >-o (OR operators) stops after the first to evaluate to TRUE.
In brief I need this command :
find "path" "list of directories to ignore" and "list files to ignore" "pass result to function"
find "path" "FILTER_1" some_operator "FILTER_2" "pass result to function"
I want to ignore all directories enumerated in filter 1 (this work)
FILTER_1 is a list of directories
I want to ignore all files enumerated in filter 2 (this does not work together with FILTER_1)
FILTER_2 is a list of files

I have succeed with this command :
Code:
find "$MY_PATH"  -type d \( $FILTRE_1  \) -prune -o -exec bash -c 'CHERCHE "$0" '  {} \;

or
Code:
find "$MY_PATH"  \( $FILTRE_2 -exec bash -c 'CHERCHE "$0" '  {} \;

but not with
Code:
find "$MY_PATH"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_2 -exec bash -c 'CHERCHE \$0 '  {} \; \)

>- How are the two code snippets in above related? What and/or where is filter 5?
It is a typo error. you may read 2,3,4

>- Why does filter 2 work in the first snippet but doesn't in the second.
That the subject of my question.
How to convert this
Code:
CMD="find \"$MY_PATH\"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_2 -exec bash -c 'CHERCHE \$0 '  {} \; \)  " 
echo "COMMAND : $CMD" 
eval "$CMD"

by
Code:
find "$MY_PATH"  -type d \( $FILTRE_1  \) -prune -o  \( $FILTRE_2 -exec bash -c 'CHERCHE "$0" '  {} \; \)

FILTER_3 and FILTER_4 are the same filter but I try different manner to quote variable string.

---------- Post updated at 12:02 ---------- Previous update was at 11:36 ----------

Quote:
Originally Posted by Chubler_XL
I believe you don't need any quotes around the -name parameters as shell will expand the variables into a single argument anyway
You need quote if * is present
Code:
@ASUS-JC-NEW:~> find . -maxdepth 1 -name ".*"
.
./.config
./.fonts
./.local
./.bash_history

Code:
@ASUS-JC-NEW:~> find . -maxdepth 1 -name .*
find: paths must precede expression: ..
Usage: find [-H] [-L] [-P] [-Olevel] [-D help|tree|search|stat|rates|opt|exec] [path...] [expression]

and from manpage
Quote:
-name pattern
Base of file name (the path with the leading directories removed) matches shell
pattern pattern. Because the leading directories are removed, the file names
considered for a match with -name will never include a slash, so `-name a/b'
will never match anything (you probably need to use -path instead). The
metacharacters (`*', `?', and `[]') match a `.' at the start of the base name
(this is a change in findutils-4.2.2; see section STANDARDS CONFORMANCE below).
To ignore a directory and the files under it, use -prune; see an example in the
description of -path. Braces are not recognised as being special, despite the
fact that some shells including Bash imbue braces with a special meaning in
shell patterns. The filename matching is performed with the use of the
fnmatch(3) library function. Don't forget to enclose the pattern in quotes in
order to protect it from expansion by the shell
.
---------- Post updated at 12:12 ---------- Previous update was at 12:02 ----------

Thank you very much for your effort.
But I have to draw your attention on two things :
1) FILTER_2 is a list of files and then ".Xauthority,.xsession1,.bash_history" are files.
2) My real problem is when I try to add a second predicate (list of files in FILTER_2) after the first predicate ( FILTER_1 )

---------- Post updated at 12:24 ---------- Previous update was at 12:12 ----------

Quote:
Originally Posted by Don Cragun
Given that there is no way to know what files might be present in the directory in which this script might be run, to guarantee that you won't get a syntax error in find if .direct* or .xsession* expand to more than one filename, and to guarantee that all files with the desired names will be matched if either of those patterns match a single filename in the current directory ...............
If I run my command with FILTER_2 alone like this :
Code:
find "$MY_PATH"  \( $FILTRE_2 -exec bash -c 'CHERCHE "$0" '  {} \;

I did not get error, and the files
.xsession-errors
.xsession-errors-:0
are exclude as expected.

FILTER_2, FILTER_3 and FILTER_4 are the same filters but quoting is different.
But none give me the expected result.
FILTER_2 works only when I use
Code:
eval "$CMD"


Last edited by rbatte1; 02-10-2017 at 09:32 AM.. Reason: Added some ICODE tags
# 7  
Quote:
Originally Posted by Don Cragun
Given that there is no way to know what files might be present in the directory in which this script might be run, to guarantee that you won't get a syntax error in find if .direct* or .xsession* expand to more than one filename, and to guarantee that all files with the desired names will be matched if either of those patterns match a single filename in the current directory, I think it would be safer to change:
Code:
F2=(! -name .direct*  ! -name .Xauthority  ! -name .xsession*  ! -name .bash_history -print)

in the code Chubler_XL suggested in post #4 to:
Code:
F2=(! -name '.direct*'  ! -name .Xauthority  ! -name '.xsession*'  ! -name .bash_history -print)

(quoting those two filename matching patterns).
It still seems to match files in the current directory when expanding ${F2[*]}, only thing that I could find to avoid it was set -f:


Code:
$ MY_PATH=/tmp/jc\ dole
$ mkdir -p "$MY_PATH"/{test,.local/share/{kscreen,ballo},.dbus}/{test{1,2},.direct{A,B,C},.Xauthority,.xsession1,.bash_history}
$ F1=( -path "$MY_PATH"/.local/share/kscreen -o -path "$MY_PATH"/.local/share/ballo -o -path "$MY_PATH"/.dbus )
$ F2=(! -name '.direct*'  ! -name .Xauthority  ! -name '.xsession*'  ! -name .bash_history)
$ OLDIFS=$IFS
$ IFS=
$ touch .xsession_test
$ find "$MY_PATH"  -type d \( ${F1[*]} \)  -prune -o \( ${F2[*]} -print \)
/tmp/jc dole
/tmp/jc dole/.local
/tmp/jc dole/.local/share
/tmp/jc dole/test
/tmp/jc dole/test/.xsession1
/tmp/jc dole/test/test1
/tmp/jc dole/test/test2
$ IFS=$OLDIFS


Last edited by Chubler_XL; 02-10-2017 at 09:39 AM..
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