[SOLVED] Using rename to replace a string that begins with a -

scasey · 07-07-2017, 06:18 PM

Quote:

Originally Posted by jpollard

using -- doesn't always work, it depends on the utility. It will USUALLY work with the GNU tools, but there are exceptions.
[snip by Sean -- see post #14]

Yet another lesson learned. Thank you very much!!

This has been a very educational thread!!

RandomTroll · 07-08-2017, 09:17 AM

Quote:

Originally Posted by jpollard

The simpler solution is "./-xxxx"

This does not address my question: I asked about replacing a string, not specifying set of files.

jpollard · 07-08-2017, 04:49 PM

Quote:

Originally Posted by RandomTroll

This does not address my question: I asked about replacing a string, not specifying set of files.

You asked.

Quote:

Sometimes I want to use rename on a group of files to replace a string that begins with a -. No kind of quoting keeps rename from treating the - as an option instead of an argument.

Since you included the second sentence, we answered. The strings you were dealing with were file names beginning with "-", which is the option indicator.

You have been give two - use the option "--" which many utilities use to indicate "no options follow". This works most of the time - but it doesn't work ALL the time. Thus I gave you the alternative of starting the file string with "./" which provides the same file using relative addressing, and does not start with "-".

Without that second sentence, you would not have been given any of the answers because using string substitution is a simple shell operation; also with multiple solutions (variable substitution, substrings, string concatenation). But that is a different problem.

Since you indicated problems with file names and options - that is a different problem, and why you got these answers instead.

RandomTroll · 07-09-2017, 12:01 AM

Quote:

Originally Posted by jpollard

The strings you were dealing with were file names beginning with "-"

No. The strings were substrings in file names, the substrings beginning with -.

Quote:

Originally Posted by jpollard

I gave you the alternative of starting the file string with "./" which provides the same file using relative addressing, and does not start with "-".

I just tried.

Code:

rename ./-2016 ./_2016 *.html

does not replace -2016 with _2016. Your solution applies only to the names of the target files, not the issue I raised.

Quote:

Originally Posted by jpollard

Since you indicated problems with file names and options - that is a different problem, and why you got these answers instead.

I indicated no problem with file names but with the way rename treats arguments that happen to be in file names.

Jjanel · 07-09-2017, 03:10 AM

From man rename, 'expression' seems to be (sort-of anyway) a 'mini-regex',
so it can't handle ./whatever (tho the 3rd arg, the filenames, can be ./stuff)
Those 2 expression replacement operate on just the name, not shell directory syntax!
Like sed s/expression/replacement/

rename -v -- - _ -
worked for me, and renamed my `mkdir -- -` to a dir named underscore

The -- is needed by getargs/getopts, to stop 'switch processing'.

So, to 'null-out' the first dash/hyphen, try: rename -v -- - '' <normal shell filename pattern>
First check: ls -d -- <that patttern, like -myODDfileORdirName>

errors&all, but this shows 'proof' (on Slackware

)

Code:

login as: user
user@127.0.0.1's password:
Last login: Wed Mar  1 09:15:15 2017
Linux 4.4.14.
user@darkstar:~$ ls
PACKAGES.TXT  myjunk  z  zfind  zloc
user@darkstar:~$ mkdir -- -mydir; touch -myfile1 my-file2 myfile3- myfile4--
touch: invalid option -- 'y' EDITNOTE: needed -- so -my... NOT switches!
Try 'touch --help' for more information.
user@darkstar:~$ touch -- -myfile1 my-file2 myfile3- myfile4--
user@darkstar:~$ ls
-mydir/   PACKAGES.TXT  myfile3-   myjunk  zfind
-myfile1  my-file2      myfile4--  z       zloc
user@darkstar:~$ rename -- -v - '' *my*
user@darkstar:~$ ls #ooops, -- stopped the -v AND made -v THE expr!
-mydir/   PACKAGES.TXT  myfile3-   myjunk  zfind
-myfile1  my-file2      myfile4--  z       zloc
user@darkstar:~$ rename -v --  - '' *my*
`-mydir' -> `mydir'
`-myfile1' -> `myfile1'
`my-file2' -> `myfile2'
`myfile3-' -> `myfile3'
`myfile4--' -> `myfile4-'
user@darkstar:~$ ls
PACKAGES.TXT  myfile1  myfile3   myjunk  zfind
mydir/        myfile2  myfile4-  z       zloc
user@darkstar:~$

Hmmm.../ooops: the regex 'magic' seems to be more than I thought:

Code:

user@darkstar:~$ rm myf*; rmdir mydir
user@darkstar:~$ mkdir -- -mydir; touch -- -myfile1 my-file2 myfile3- myfile4--
user@darkstar:~$ rename -v --  './-' '' ./*my*
`./-mydir' -> `mydir'
`./-myfile1' -> `myfile1'
user@darkstar:~$

Ok, overSolved

Then there's always util-linux/rename.c