Shell Programming and Scripting

Backslashes work with the parentheses. However, it does not work with \|.
a|b will treat | as a string and a\|b will treat | as special character. but I couldn't find it's meaning in help manual and \| does not work like or.
I have also been researching online.
I'm desperate

Since I already have sed code for editing other stuffs in the file. Using sed would save me many lines of work. I'm not very familiar with awk and cut, but if I still couldn't get sed to work this afternoon, I'm willing to try anything.

As a really crude hack you could combine the month names into one monster regular expression, with a slight risk of false positives.

Here's a schematic picture:

Code:

J     a    n
J    u    n
J    u    l
F    e    b
M    a    r
M    a    y
A    p    r
A    u    g
S    e    p
O    c    t
N    o    v
D    e    c
------------
JFM  aue nlb
ASO pco ryg
ND     ptvc

That probably comes out hideously ugly, but the basic observation is that the first character of a month name can be J or F or M or A or S or O or N or D, and so on for the second and third letters. So you could lump them together and just accept the risk that somebody writes something which begins with Jay or Opp and happens to look enough like a date to trigger a false match.

[ADFJMNOS][aceopu][bcglnprtvy]

Hope I didn't miss any.

I would not do this, but you said you were desperate ... at that point the awk or cut commands hinted at above would seem like better solutions.

Just out of curiosity, which platform is this on? Does sed --version print anything useful? Does which sed or type sed reveal any alternate seds in your PATH which might work better?

I'm working on Solaris and sed --version does not print anything useful.
I also had the idea of doing something like [ADFJMNOS][aceopu][bcglnprtvy], but it's very risky since I'm edit a database file which contains lots of data.

also, another question:
(Jan or Feb or...) (1 space or two space) ([0-9][0-9] or [0-9]) [12][0-9][0-9][0-9]
For example, the data format can be Mar 26 2008, Mar 6 2008, Mar 6 2008.
Do you have any good suggestion about (1 space or 2 space) ([0-9][0-9] or [0-9]) part without using \|?

Thank you for my life lol

Code:

 [ 0-9]?[0-9]

The ? operator means the previous character is optional but if your sed is really old, itmight not understand that either. (Some seds want a backslash in order to make the question mark special, too.) There's a space there before the first visible character.

You could still try the following, in increasing order of desperation.

Code:

locate bin/sed
locate bin/gsed
ls -l /opt/contrib/unsupported/dangerous/communist/contraband/hate/hate/hate/gnu/bin/sed  # long shot (-:
find / \( -name sed -o -name gsed \) >/tmp/found.sed 2>/dev/null &  # leave it for the night

ah~u r right, ? also doesnt work. I will try the long code tonight.
Thank you