Triple nested quotations in shell script

问题

I'm trying to write a shell script that calls another script that then executes a rsync command. The second script should run in its own terminal, so I use a gnome-terminal -e "..." command. One of the parameters of this script is a string containing the parameters that should be given to rsync. I put those into single quotes. Up until here, everything worked fine until one of the rsync parameters was a directory path that contained a space. I tried numerous combinations of ',",\",\' but the script either doesn't run at all or only the first part of the path is taken.

Here's a slightly modified version of the code I'm using

gnome-terminal -t 'Rsync scheduled backup' -e "nice -10 /Scripts/BackupScript/Backup.sh 0 0 '/Scripts/BackupScript/Stamp' '/Scripts/BackupScript/test' '--dry-run -g -o -p -t -R -u --inplace --delete -r -l '\''/media/MyAndroid/Internal storage'\''' "

Within Backup.sh this command is run

rsync $5 "$path"

where the destination $path is calculated from text in Stamp.

How can I achieve these three levels of nested quotations?

These are some question I looked at just now (I've tried other sources earlier as well)

https://unix.stackexchange.com/questions/23347/wrapping-a-command-that-includes-single-and-double-quotes-for-another-command
how to make nested double quotes survive the bash interpreter?
Using multiple layers of quotes in bash
Nested quotes bash

I was unsuccessful in applying the solutions to my problem.

回答1:

Here is an example. caller.sh uses gnome-terminal to execute foo.sh, which in turn prints all the arguments and then calls rsync with the first argument.

caller.sh:

#!/bin/bash
gnome-terminal -t "TEST" -e "./foo.sh 'long path' arg2 arg3"

foo.sh:

#!/bin/bash
echo $# arguments
for i; do    # same as: for i in "$@"; do
    echo "$i"
done
rsync "$1" "some other path"

Edit: If $1 contains several parameters to rsync, some of which are long paths, the above won't work, since bash either passes "$1" as one parameter, or $1 as multiple parameters, splitting it without regard to contained quotes.

There is (at least) one workaround, you can trick bash as follows:

caller2.sh:

#!/bin/bash
gnome-terminal -t "TEST" -e "./foo.sh '--option1 --option2 \"long path\"' arg2 arg3"

foo2.sh:

#!/bin/bash
rsync_command="rsync $1"
eval "$rsync_command"

This will do the equivalent of typing rsync --option1 --option2 "long path" on the command line.

WARNING: This hack introduces a security vulnerability, $1 can be crafted to execute multiple commands if the user has any influence whatsoever over the string content (e.g. '--option1 --option2 \"long path\"; echo YOU HAVE BEEN OWNED' will run rsync and then execute the echo command).

回答2:

Did you try escaping the space in the path with "\ " (no quotes)?

gnome-terminal -t 'Rsync scheduled backup' -e "nice -10 /Scripts/BackupScript/Backup.sh 0 0 '/Scripts/BackupScript/Stamp' '/Scripts/BackupScript/test' '--dry-run -g -o -p -t -R -u --inplace --delete -r -l ''/media/MyAndroid/Internal\ storage''' "

来源：https://stackoverflow.com/questions/21168817/triple-nested-quotations-in-shell-script

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Linux

string

bash

shell

nested