running bash script from within octave / matlab getting error executing bash syntax error near unexpected token `('

问题

I get the error executing bash syntax error near unexpected token `('

I know the error is caused by the ')' but I thought placing the commands in-between ' ' is suppose to allow the parenthesis in a directory name. How can I fix this without renaming the name?

The matlab / octave code is:

syscmd=strcat({'bash -c '},{''''},{'cd '},dirpathpls,newdirname,{' && exec bash xfade.sh'},{''''}) %used to run script to join files in stretch directory
system(syscmd);

and it produces what is below:

bash -c 'cd /tmp/h1/clients/04212015142432811_Fs_1000_ahh/pls/03sox_a_Fs_1000_ahh_(000_bit)_(0.0000
0sig_in_deg)_to_(508_bit)_(30.00000sig_in_deg) && exec bash xfade.sh'

please note: It's being called from inside octave 3.8.1 a math program like matlab

回答1:

Using ' within a bash command line does allow the use of reserved characters like ( without escaping; however, that is not what you are doing. Everything within your 's is being passed to bash for interpretation, bash isn't interpreting the 's as part of the command. Something like this should work:

syscmd=strcat({'bash -c '},{''''},{'cd "'},dirpathpls,newdirname,{'" && exec bash xfade.sh'},{''''}) %used to run script to join files in stretch directory
system(syscmd);

I don't know matlab/octave, but I hope that conveys the idea. The " should effectively escape the parens. The only pitfall there is if your directory name might have a $ or " in it, in that case, or you have ' AND " in your dir name, things are going to get silly.

回答2:

As I told you in your other question on this topic: Don't use bash -c; it's not necessary for octave to run an external command, and you're doing nothing but making your life harder by trying.

command=strcat({'cd '''},
           strrep(strcat(dirpathpls,newdirname),
                  '''',
                  '''"''"'''''),
           {''' && exec bash xfade.sh'})
system(syscmd);

Two key differences:

We're using the sh -c implicitly created by the system() call
We're escaping the filenames, preventing any malicious content within them from escaping the quotes and being executed.

How that escaping works:

Single-quoted strings in POSIX shells are ended only by a following single-quote. To insert a literal single quote into them, one needs to end the single-quoted string and then enter a different quoting type. Thus:

'"'"'

...in which the first ' ends the prior quoting type; the " enters a double-quoted context (in which a single-quote literal can be recognized; the ' after it is then your literal single-quote character; the " following ends the double-quoted context, and the final ' resumes a single-quoted context.

This is all made more complicated by doubling the 's to ''s for Octave's syntax; this is how one gets

strrep(content, '''', '''"''"''''')

...to replace all 's with '"'"'s.

来源：https://stackoverflow.com/questions/29781414/running-bash-script-from-within-octave-matlab-getting-error-executing-bash-syn

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