UNIX for Dummies Questions & Answers

Hello,

This is my first post so, Hello World! Anyways, I'm learning how to use unix and its quickly become apparent that a strong foundation in regular expressions will make things easier. I'm not sure if my syntax is messing things up or my logic is messing things up.

Code:

ps -e | grep '\b[1-9][0-9]\{3,}\b'

So, I want a list of most of the current processes ps -e generates a list similar to the one below but with more lines.

Pattern: I want to reduce the output to only include lines that have numbers greater than 1000.
Program: I'll use grep to print the lines matching the above pattern.
Options: I don't think I need to use any options.
Regular Expression: \b[1-9][0-9]\{3,}\b
File: ps -e (omitted)

Again the fully command line argument(?correct term) is:

Code:

ps -e | grep '\b[1-9][0-9]\{3,}\b'

I read the regular expression as:
\b: Check for world boundary before the string.
[1-9]: The first character in the string must be between 1 and 9.
[0-9]: The second character in the string must be between 0 and 9.
\{3,}: Replaces the above statement with: The characters following the first match must match between 0 and 9 at least 3 more times.
Kinda would look like \b[1-9][0-9][0-9][0-9]\b (for the min)
\bCheck for word boundary at the end of the string.

The return I get is:
I'm probably missing something simple but I can't figure it out.

The repetition code was taken from http://www.regular-expressions.info/repeat.html and altered a bit to apply to a use that I could create.
I also referenced the grep - Linux Command - Unix Command for info on grep.

Hi MykC, You were just one \ away

Code:

grep '\b[1-9][0-9]\{3,\}\b'

Hi.

Given that no number starts with 0 with ps -e, you could simply say:

Code:

ps -e | grep "^ *[0-9]\{4,\}"

Awk is great for this kind of thing:

Code:

ps -e | awk '$1*1 >= 1000'

(*1 removes the heading by turning into a number, which is then undefined)

And then you could leave out the comma too:

Code:

ps -e | grep "^ *[0-9]\{4\}"

or even 4 characters that are no space.

Code:

ps -e | grep "^ *[^ ]\{4\}"

( and since the first field is right aligned and the max pid is 99999:

Code:

ps -e|grep '^.[^ ]'

or filter out lines that start with two spaces:

Code:

ps -e|grep -v '^  '

but that is stretching it a little and probably not very portable )

Hey, thanks for the help, such a silly error.