08-24-2010
The problem is that file I/O has no "insert" operation: If the new data is a different length than the old you need to rewrite everything after the change.
There's way better, faster, and simpler ways than the 'cut' utility to read fields from a data file, but it's difficult to help without seeing the rest of your program. It'd also tell me what other fields from that line you have, since just knowing the balance isn't enough to find and edit that exact line...
This User Gave Thanks to Corona688 For This Post:
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi,
I wrote a script which extracts data from 2 tables (joining the tables together) and outputs the fields to a csv file.
the output may look something like
scenario 1: a,b,c,d,1,2,3,4 or
scenario 2: a,b,c,d,,,,
now, in the second scenario, there are some empty fields at the end of... (3 Replies)
Discussion started by: Darek
3 Replies
2. UNIX for Dummies Questions & Answers
hi,
i currently have a file with columns similar to this
customer name owed
CID123 John 300
CID342 harry 500
at present i use use awk to find the amount owed by the customer using the customer ID (CID).
if the customer spends more money how would i go about using sed/awk etc to... (2 Replies)
Discussion started by: skinnygav
2 Replies
3. Shell Programming and Scripting
Hi Guys,
I have a file like this:
aaa b c d e f
fsss g h i k l
qqq r t h n
I want:
aaa b c d e f
fsss g h i k l
qqq r t h , n
ggg p t e d u
qqq i o s , k (2 Replies)
Discussion started by: npatwardhan
2 Replies
4. Shell Programming and Scripting
Hi,
I'm attempting to rename some files that have spaces in them. Without linking sed commands together is it possible to replace the first three "." to " ".
File.name.is.long.ext -> File name is long.ext
I can get the desired effect with
echo "File.name.is.long.ext" | sed 's/\./ /g;s/... (5 Replies)
Discussion started by: vectox
5 Replies
5. Shell Programming and Scripting
Say the input was as follows:
Brat 20 x 1000 32rf
Pour 15 p 1621 05pr
Dart 10 z 1111 22xx
My program prompts for an input, what I want is to use the input to locate a specific field. Like if I type in, "Pou" then it would return "Pour" and just "Pour"
I currently have this line but it is... (6 Replies)
Discussion started by: Bungkai
6 Replies
6. Shell Programming and Scripting
I'm trying to update a text file via sed/awk, after a lot of searching I still can't find a code snippet that I can get to work.
Brief overview:
I have user input a line to a variable, I then find a specific value in this line 10th field in this case. After asking for new input and doing some... (14 Replies)
Discussion started by: crownedzero
14 Replies
7. Shell Programming and Scripting
I have a text file like this:
subject1:LecturerA:10
subject2:LecturerA:40
if I was given string in column 1 and 2 (which are subject 1 and LecturerA) , i need to update 3rd field of that line containing that given string , which is, number 10 need to be updated to 100 ,for example.
The... (6 Replies)
Discussion started by: bmtoan
6 Replies
8. Shell Programming and Scripting
Hi All,
I am very new to shell scripting and tried to search this in the forum but no luck.
Requirment:
I have an input file which is comma separated. I need to replace the value in 4th column with another value. This has to happen for all the lines in the file.
Sample data:
Input... (2 Replies)
Discussion started by: arunkumarsd
2 Replies
9. Shell Programming and Scripting
Greetings.
I've got a csv file with data along these lines:
Spumoni's Pizza Place, Placemats n Things, Just Lamps
Counterfeit Dollars by Vinnie, Just Shades, Dollar StoreI want to replace the entire comma-delimited field if it matches something ending in "Place" or beginning with "Dollar",... (2 Replies)
Discussion started by: palmfrond
2 Replies
10. UNIX for Beginners Questions & Answers
I'm new with scripting and I can't seem to figure out what I should do to get the output that I want.
My file content would be below.
ID2|ID3 |ID4|ID5 |
I'm trying to replace the field of ID3 which has a fixed length of 10 characters, for each entry I have placed on a .txt file... (5 Replies)
Discussion started by: asdfghjkl
5 Replies
CUT(1) BSD General Commands Manual CUT(1)
NAME
cut -- select portions of each line of a file
SYNOPSIS
cut -b list [-n] [file ...]
cut -c list [file ...]
cut -f list [-d delim] [-s] [file ...]
DESCRIPTION
The cut utility selects portions of each line (as specified by list) from each file and writes them to the standard output. If the file
argument is a single dash ('-') or no file arguments were specified, lines are read from the standard input. The items specified by list can
be in terms of column position or in terms of fields delimited by a special character. Column numbering starts from 1.
list is a comma or whitespace separated set of increasing numbers and/or number ranges. Number ranges consist of a number, a dash (-), and a
second number and select the fields or columns from the first number to the second, inclusive. Numbers or number ranges may be preceded by a
dash, which selects all fields or columns from 1 to the first number. Numbers or number ranges may be followed by a dash, which selects all
fields or columns from the last number to the end of the line. Numbers and number ranges may be repeated, overlapping, and in any order. It
is not an error to select fields or columns not present in the input line.
The options are as follows:
-b list The list specifies byte positions.
-c list The list specifies character positions.
-d string Use the first character of string as the field delimiter character. The default is the <TAB> character.
-f list The list specifies fields, separated by the field delimiter character. The selected fields are output, separated by the field
delimiter character.
-n Do not split multi-byte characters.
-s Suppresses lines with no field delimiter characters. Unless specified, lines with no delimiters are passed through unmodified.
EXIT STATUS
cut exits 0 on success, 1 if an error occurred.
SEE ALSO
paste(1)
STANDARDS
The cut utility conforms to IEEE Std 1003.2-1992 (``POSIX.2'').
BSD
December 21, 2008 BSD