sed replace strings with single quotes and brackets

[Harry]

I am trying to modify a whole bunch of text files (*.sh)
with a small shell script.

$ cat yy
SRC="new_time(tx.create_dt_tm,'GMT','TIMEZONE')"
DEST="cast(from_tz(cast(tx.create_dt_tm as timestamp), 'Etc/GMT0') at time zone 'Canada/Pacific' as date)"
for i in *.sh
do
echo modifying $i ...
sed -i "s/$SRC/$DEST/g" $i
done

I got errors like these ... what am I missing ?

modifying xxx.sh ...
sed: -e expression #1, char 100: unknown option to `s'

Note: both $SRC and $DEST have no double quotes in the string contents.

TIA

[David W. Hodgins]

Run it with "bash -x -v yy"

+ for i in *.sh
+ echo modifying newcerts.sh ...
modifying newcerts.sh ...
+ echo sed -i 's/new_time(tx.create_dt_tm,'\''GMT'\'','\''TIMEZONE'\'')/cast(from_tz(cast(tx.create_dt_tm as timestamp), '\''Etc/GMT0'\'') at time zone '\''Canada/Pacific'\'' as date)/g' newcerts.sh
sed -i s/new_time(tx.create_dt_tm,'GMT','TIMEZONE')/cast(from_tz(cast(tx.create_dt_tm as timestamp), 'Etc/GMT0') at time zone 'Canada/Pacific' as date)/g newcerts.sh

Notice how the generated sed command contains too many slash characters.

Replace the delimiter slash characters with some other character not present in the
strings.

Regards, Dave Hodgins

[Harry]

On Tuesday, November 9, 2021 at 1:14:37 PM UTC-8, David W. Hodgins wrote:

> Run it with "bash -x -v yy"
>
> + for i in *.sh
> + echo modifying newcerts.sh ...
> modifying newcerts.sh ...
> + echo sed -i 's/new_time(tx.create_dt_tm,'\''GMT'\'','\''TIMEZONE'\'')/cast(from_tz(cast(tx.create_dt_tm as timestamp), '\''Etc/GMT0'\'') at time zone '\''Canada/Pacific'\'' as date)/g' newcerts.sh
> sed -i s/new_time(tx.create_dt_tm,'GMT','TIMEZONE')/cast(from_tz(cast(tx.create_dt_tm as timestamp), 'Etc/GMT0') at time zone 'Canada/Pacific' as date)/g newcerts.sh
>
> Notice how the generated sed command contains too many slash characters.
>
> Replace the delimiter slash characters with some other character not present in the
> strings.

Thanks, I replace / with # in the sed cmd and it works now.

[applemcg]

anytime there's a potential file path involved mine looks like

sed "s=$this=$that="

suggesting a function:

psed () { : path-protected sed; sed "s=$1=$2=g" ; }

[Janis Papanagnou]

On 13.11.2021 16:35, applemcg wrote:
> On Tuesday, November 9, 2021 at 5:25:28 PM UTC-5, Harry wrote:
>> On Tuesday, November 9, 2021 at 1:14:37 PM UTC-8, David W. Hodgins wrote:

>>> [ slash characters in sed substitution and as sed separators ]

>>> Notice how the generated sed command contains too many slash characters.
>>>
>>> Replace the delimiter slash characters with some other character not present in the
>>> strings.
>> Thanks, I replace / with # in the sed cmd and it works now.
>
>
> anytime there's a potential file path involved mine looks like
>
> sed "s=$this=$that="
>
> suggesting a function:
>
> psed () { : path-protected sed; sed "s=$1=$2=g" ; }
>

Functions should be suggested if they are generally applicable.
Your code shows the same issue with '=' characters that the OP
had with '/' characters. (Consider path-component data with '='
and $this or $that containing a '='.)

Taking another rare character might delay the failure further but
not solve the task generally.

Janis

[applemcg]

of course; one might defend oneself against a range of unlikely characters
using a CASE statement.

my last gainful employ was as trainer at a wall st fin svcs company. our
help desk, operating on Windows, trying to read log files with date stamps in their
name were relieved to see a file system where the HH:MM:SS's were linked with LN(1),
to an HH_MM_SS named file sometimes the fix lies elsewhere.

[Janis Papanagnou]

On 13.11.2021 18:19, applemcg wrote:
>>>>> [ slash characters in sed substitution and as sed separators ]
>>

>> Taking another rare character might delay the failure further but
>> not solve the task generally.
>

> of course; one might defend oneself against a range of unlikely characters
> using a CASE statement.

Or dynamically checking the $this and $that values in the function.
Even using binary separator values might fail in pathological cases,
though using something like sed s$'\1'"$this"$'\1'"$that"$'\1'
certainly fails much rarer.

>
> my last gainful employ was as trainer at a wall st fin svcs company. [...]

(I cannot decipher "st fin svcs". - Ah, wait! Now I've got it.)

Janis

[Stonebridge Mens Club]

Janis,

If I may, I'll disagree slightly with the idea that "Functions should

be suggested if they are generally applicable"

You have noticed a practice of mine: precede a command name with a
single letter to isolate a specific use of an idea, in this case psed.

I've a small family of awk wrappers: cawk, pawk, and tawk. a clue to
their usage:

tawk () { awk -F'\t' "$@"; }

"pawk" got quite a bit of use when i was at the T (at&~), since
pipe-separated tables were widely in use there.

"cawk" _never_ gets used. There seems to be no standard for the CSV
file. i.e. what if a field has a comma in it?

"tawk" has no such problems. there will never be a TAB in data field.
IBM saw to that with the 3270 terminal, since the TAB character (on
that machine) was designed to take the user to the next data input
field. And ...

I met Rod Manis, one of three authors of "Unix Relational Data Base
Management", which produced the text-only data base management system
/rdb. He gave me a draft of their book, ~ '86, and I produced a KSH
version. Where awk is the engine. Manis was dogmatic about little:

"There will never be a TAB character in a data field"

I'm at last producing a bash version -- annotated -- since a great
deal of the book is either obsolescent or application-specific, with
too much to do with accounting.

[Janis Papanagnou]

On 15.11.2021 16:39, Stonebridge Mens Club wrote:
>
> If I may, I'll disagree slightly with the idea that "Functions should
> be suggested if they are generally applicable"

The point in this thread was that the function was written to solve a
task but did that in an inherently error prone way. Please read this
statement in that context.

Janis

[Keith Thompson]

Stonebridge Mens Club <sbmc...@gmail.com> writes:
[...]

> "cawk" _never_ gets used. There seems to be no standard for the CSV
> file. i.e. what if a field has a comma in it?

As I recall there are multiple standards for CSV files.

The most nearly definitive is probably RFC 4180.

https://www.ietf.org/rfc/rfc4180.txt
https://datatracker.ietf.org/doc/html/rfc4180

--
Keith Thompson (The_Other_Keith) Keith.S.T...@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

[Lew Pitcher]

On Mon, 15 Nov 2021 12:16:36 -0800, Keith Thompson wrote:

> Stonebridge Mens Club <sbmc...@gmail.com> writes: [...]
>> "cawk" _never_ gets used. There seems to be no standard for the CSV
>> file. i.e. what if a field has a comma in it?
>
> As I recall there are multiple standards for CSV files.
>
> The most nearly definitive is probably RFC 4180.
>
> https://www.ietf.org/rfc/rfc4180.txt
> https://datatracker.ietf.org/doc/html/rfc4180

Caveat from https://www.ietf.org/rfc/rfc4180.txt:

Status of This Memo

This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.


--
Lew Pitcher
"In Skills, We Trust"

[Kaz Kylheku]

On 2021-11-15, Stonebridge Mens Club <sbmc...@gmail.com> wrote:
> I've a small family of awk wrappers: cawk, pawk, and tawk. a clue to
> their usage:
>
> tawk () { awk -F'\t' "$@"; }
>
> "pawk" got quite a bit of use when i was at the T (at&~), since
> pipe-separated tables were widely in use there.
>
> "cawk" _never_ gets used.

You tawk the tawk, but don't get to pawk your cawk?

That's more than I want to know about the affairs of the
Stonebridge Mens Club.