Programming :: Best Command To Use To Parse Strings?
Mar 24, 2010
what is the best command to use to parse strings?I have a variable $str and need to parse this string.Can you provide an example of the command used to get a substring of $str based on the index values of start and end
I use udhcp with some of my minimal installs. I've messed around with the code a bit when it wasn't working correctly - a few years ago. I will find time - I hope soonish - to figure out how to do a few other things with it.
For now though, I'm using this string to grab my ip after startup
I realize I could substitute ifup -a but I'm more interested in figuring out how to make ifup wait for the ip to become available if it is not available yet.
Never mind that one, just typing out the question answered it for me, when I find it in the scripting man ' ; : " & =
Or if there are any other suggestions for better construction of the string.
I want to search and replace strings in a file with strings in other files/i need to do it with big strings(string1 is big) and i want to use a txt file for this.But this code not working :
I am having a lot of problems trying to change one string by another using sed: the sentence is like this:
sed -i 's/KERNEL=="tty[A-Z]*", NAME="%k", GROUP="uucp", MODE="0660"/KERNEL=="tty[A-Z]*", NAME="%k", GROUP="uucp", MODE="0666"/g' 50-udev.rules it is just to fing the line with: KERNEL=="tty[A-Z]*", NAME="%k", GROUP="uucp", MODE="0660"
I wrote this small program that will truncate a string that's entered in by the user.An example of its usage:if the user enters in a string say "abcdefghijklmnopqrstuvwxyz" the program will only take the first 9 characters and truncate the rest so that the user can be prompted for a second string and not be worried about remaining characters left in the stream.Now this program works O.K. but I would like to find something in C that has this functionality build into it...Does anyone know of any function that will accomplish this.
I am trying to replace a section of a file between the first instances of the strings {}, with the contents of another file. Example of the format of the file I'm trying to modify
I have a PHP script written that is checking a string to see if it contains a link in it (i.e. a URL). I have the following if statement, that uses 3 possible regular expressions to determine if there is a link or not.
Code: // check if we found a link // links are denoted by strings that: // - contain http:// // - contain www.*.*
[Code]....
I'm not convinced yet that writing a shell script to do this is the best course of action. If someone is capable of doing this with a Perl or a Python script that's fine too. If you want to make it super high performance and write it in assembly
i have an sql table with 2 columns i run a script that randomly selects a word from the table in column 1. the word is displayed on the screen and I guess what it means i concatenate the randomly selected word and the answer the script looks for a match in mysql if it finds a match it says "Good job!" if there is no match it will say "not correct". However when i get it right it says not correct even though when i echo the variables they look exactly the same. the script below:
#!/bin/bash var=$(mysql translator -u root --password=*-N<<EOF SELECT word FROM tagalog ORDER BY RAND() LIMIT 1 EOF )
I have a function that retrives text between title and links tags from an XML file, but what i want is to test if the title and link tags are between item tags. This is my code:
With opensuse11.2 I am getting following error while running openGL apps: drmRadeonCmdBuffer: -22. Kernel failed to parse or rejected command stream. See dmesg for more info. I think this is problem with radeon drivers. Is there solution to this?
Given that I want my shell script be invoked at the command line using the above parameters - where [these brackets] denote that they are optional - what is the best method to parse them?
I am trying a search for a pattern in the file. I can have any character in the pattern. I am pretty sure I will have $, ", ', ^, ` etc., The Problem I am facing is if I use "" (double quotes) to enclose the pattern, it gives special meaning to $, ^ and " within the string. I have no control over the pattern input. I am getting it from some other file. On the other hand, If I use '' (single quotes) to enclose the pattern, it gives special meaning to the ' (apostrophe) within the string and terminates the pattern prematurely. How do I disable the special meaning these characters have? For example, in perl, I could enclose the pattern within Q and E. Is there an equivalent in grep pattern expression? I could find one in the man page of grep. Is there a solution to this problem?
I need to make a daemon which listens to port 81 for messages like [URL] So far I made a daemon which serves as a simple stream server: I set up a socket to listen to a non-reserved port (like 9999), but I don't know how to read the query strings.
I have an interpteter that supports string literals, and the way it works is that the lexer returns the entire string as a single token, with the quotes removed and escape sequences replaced with the literal characters they represent.
I already implemented single-quote strings, they don't interpret any characters specially except for the single quote. I partially implemented double-quoted strings, they already support all the same backslash escape sequences that C does. But I would also want to add variable substitution.
The way it would work is that "${expression}" would interpret the expression (which could just be a variable name) and replace itself with the result. But I have no idea how to do this.
In case it matters, I'm using a hand-written lexer and recursive-descent parser.
I am no expert in loops and it took me all day to write that. I couldn't really tell how to match the string in $df_file and $fs_share, so I did a little workaround with a count.
I was zsync-ing the latest Ubuntu 11.10 Alpha and thought I'd make a little GUI for it as a small project. The gui is set up, I just need to figure out how to run zsync with content from to variables, cto and cfrom. I tried the following code:
My php knowledge is very poor (only worked with strings so far), and I am faced which a task that is a real challenge for me: I have a variable, that contains data of different type, in this order: byte, byte, string, string, string, string, short, byte, byte, byte, byte, byte, byte, byte, string.
Strings are of variable length. How could this data be parsed into variables of the right type, and then all converted to strings? What are the functions to use? Strings are unicode ones, and they are delimited by "
This should be simple but I can't seem to find what I am looking for.I want to search a text file for the existence of certain strings and execute a command if they exist, something along the lines of:
if <string> exists command or
if <any member of this list exists> command
I know how to manually search a file with grep, cat, etc., but the "if this exists" part eludes me.
...and returning the index of the found element in its array.
I have:
for ((i=0; i < ${#array1[@]}; i++)); do # Read each line of the file test if [[ $(eval "sed -n '$(($i+1))'p test") == *${array2[0]}* ]] stuff
I want to find the index of the found substring in array2 and only if it isn't found, move on to the next element of array2. I don't know the size of array2 so that [0] has just got to go.
I have to parse a file containing billions of records and populate them in the Data structure. I have used a lot of C++ class and creating objects of the class I am storing the information retrieved by parsing the file.
Now as the file become huge and number of objects become very large my code is getting bad_alloc error as it is not finding any space avalable in the heap for allocating new object.
To run a parallel chemistry program, I need to build the host list. The cluster already has SGE(grid engine) installed and it generates a host list file with the following contents:
The important bits are hostname(ex compute-1-1) and number of cpus to use(ex 2). And for this program, it wants them in this form, a shell variable: HOSTLIST=hostname:cpus=X hostname:cpus=X .... I've tried this script, but it doesn't work