Is it possible to spread a sed command over multiple lines, to improve
readability (for the sake of future maintenance)? If so, what
character is used to break the line and what are the rules?

For example, I would like to re-write the command:

sed -e 's/\.//g' -e 's/\,//g' -e 's/\\//g' "$1" | sort -u > foo

as:

sed -e 's/\.//g'
-e 's/\,//g'
-e 's/\\//g' "$1"
| sort -u > foo

and be able to add additional lines such as:

-e 's/[0-9]//g'


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Russell L. Harris schrieb:
> Is it possible to spread a sed command over multiple lines, to improve
> readability (for the sake of future maintenance)? If so, what
> character is used to break the line and what are the rules?
>
> For example, I would like to re-write the command:
>
> sed -e 's/\.//g' -e 's/\,//g' -e 's/\\//g' "$1" | sort -u > foo
>
> as:
>
> sed -e 's/\.//g'
> -e 's/\,//g'
> -e 's/\\//g' "$1"
> | sort -u > foo
>
> and be able to add additional lines such as:
>
> -e 's/[0-9]//g'
>
>
>
Hello,

sure you can, just as any other command between the arguments, but not
between.
The command lines are interpreted by the shell, not by the programs,
they just get the arguments they were called with as an ordered data
package, but don't usually have anything to do with the way they were
called.
You may escape a linebreak just as any other charater in all Linux/Unix
shells I know, just remember that the <Enter> must come immediately
after the backspace:

sed -e 's/\.//g' \
-e 's/\,//g' \
-e 's/\\//g' "$1" \
| sort -u > foo

Greetings,
Björn


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Le mercredi 11 avril 2007 19:22, Russell L. Harris a écrit:
> Is it possible to spread a sed command over multiple lines, to improve
> readability (for the sake of future maintenance)? If so, what
> character is used to break the line and what are the rules?
>
> For example, I would like to re-write the command:
>
> sed -e 's/\.//g' -e 's/\,//g' -e 's/\\//g' "$1" | sort -u > foo
>
> as:
>
> sed -e 's/\.//g'
> -e 's/\,//g'
> -e 's/\\//g' "$1"
>
> | sort -u > foo
>
> and be able to add additional lines such as:
>
> -e 's/[0-9]//g'

bash simply accepts something like this:

sed /tmp/file -e '
s,h,,g
s,o,,g'

or you can put your commands in a separate file (one by line) and use -f
command-file instead of -e

in both cases, you can put several commands on the same line by separating
them with a ';'

--
Cédric Lucantis

>
> sed -e 's/\.//g'
> -e 's/\,//g'
> -e 's/\\//g' "$1"

... but also note that this can be done with a single command (escaping is
useless here) : 's/[,/.]//g'

--
Cédric Lucantis

On Wed, Apr 11, 2007 at 12:22:16PM -0500, Russell L. Harris wrote:
> Is it possible to spread a sed command over multiple lines, to improve
> readability (for the sake of future maintenance)? If so, what
> character is used to break the line and what are the rules?
>
> For example, I would like to re-write the command:
>
> sed -e 's/\.//g' -e 's/\,//g' -e 's/\\//g' "$1" | sort -u > foo
>
> as:
>
> sed -e 's/\.//g'
> -e 's/\,//g'
> -e 's/\\//g' "$1"
> | sort -u > foo

use the escape character '\' before the carriage return on the lines
and I think it should work.

sed -e 's/\.//g' \
-e 's/\,//g' \
-e 's/\\//g' "$1" \
| sort -u > foo

the \ escapes the return making the command appear as one line to
bash. make sure there are no other characters *after* the \

A

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