Using the 9base port in {Net,Free}BSD, it appears that Plan 9's sed
1. restricts the max number of sed commands and thereby the length of sed scripts
2. does not recognise the \nn flag where nn is the number of a matched substring. See example below.
Questions:
1. Why would they limit the max number of sed commands?
2. Plan 9's regexp library is not the same as BSD's? (It's probably better hence my curiosity.) So the rules of re_format(7) do not apply? Is it not possible to match substrings, as below?
Is it that the Plan 9 utils like sed and grep use ERE by default, instead of BRE? No BRE in Plan 9 utils?
I haven't played with Plan9 in a long while, but, yes, I believe there is only a single flavor of regular expression in the Plan9 ecosystem (which is a nice respite from the many flavors in POSIX and real UNIX implementations, where each of ed, ex, grep, egrep, sed, and awk prescribe their own flavor).
I'm fairly sure a left-parens is already a metacharacter, in Plan9 (as with POSIX ERE), so backslash-escaping it (as in your example) actually treats it literally.
As to the "Too many commands" message, I have no clue. Perhaps it's a syntax error and not a script length limit?
In recently reading an article on linux basics before I embark and my personal installation project I came across this passage -
IDE drives have three types of partition: primary, logical, and extended. The partition table is located in the master boot record (MBR) of a disk. The MBR is the... (12 Replies)
Hi,
I recently started working with Solaris, and what I noticed is that a lot of commands I used to regularly use don't work, like sed -i and grep -r. I have found work arounds for these problems though but it's a pain in the ass.
I'm just wondering why they decided not to include these handy... (4 Replies)
Hi,
I have noticed some performance issues on my RHEL5 server but the memory and CPU utilization on the box is fine.
I have a 1G full duplexed eth0 card and I am suspicious that this may be causing the problem. My eth0 settings are as follows:
Settings for eth0:
Supported ports: ... (12 Replies)
Hi,
I need a documentation about limitations on the linux partition. On how many primary and extended I could create. And also on different type of storage, how many big capacity I can create.
Thanks. (3 Replies)
I'm running a simulation (programmed in C) which makes calls to gnuplot periodically to plot data I have stored.
First I open a pipe to gnuplot and set it to multiplot:
FILE * pipe = popen("gnuplot", "w");
fprintf(pipe, "set multiplot\n");
fflush(pipe);
(this pipe stays open until the... (0 Replies)
I am an entry level programmer with no formal training in computer science. I am trying to enhance my conceptual knowledge about operating systems in general.
I have been using the C programming language on Linux systems for some time and have used the traditional unix stream I/O APIs. The... (1 Reply)
I would like to set my minimum password length to on Linux and AIX.
However, doing this normally would only make it so newly added users will be affected by this. I would like for when I make this change, it either truncates everyone elses password, or prompts them to change it to 8+ characters.... (2 Replies)
I am trying to use the csplit file on a file that contains records that have more than 2048 characters on a line. The resultant split file seems to ignore the rest of the line and I lose the data.
Is there any way that csplit can handle record lengths greater than 2048?
Thanks (0 Replies)
32 bit IP addresses with class based allocation schemes have limitations. does anyone know where i could get some info on this or if you have time to spare and really want to help me, a couple of sentences.
thanks
milos (1 Reply)