09-15-2009
Quote:
Originally Posted by
rhetoric101
sed completely hangs if I try to use the "\1_Q" (but works if I just use "\1Q").
You basically search for "_" and replace it with "_Q". In the next round of the loop you find what you have just replaced and replace again thereby establishing an infinite loop.
You would have to search for "_<not followed by a Q>" (in regex "_[^Q]*") to avoid that loop.
I hope this helps.
bakunin
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I built a 12 million record file and made a mistake, one field is 1 character too long.
The record is 40 bytes and ends always in 999. I am trying to delete the 37 character in each record. Is this possible without doing a cut and paste. (1 Reply)
Discussion started by: bthomas
1 Replies
2. Shell Programming and Scripting
It's all in the subject. I try to figure out how to repeat a character a number of time with printf.
For example to draw a line in a script output.
Thks (13 Replies)
Discussion started by: ripat
13 Replies
3. Shell Programming and Scripting
Hi
I need to write a script that read a input file that had same statement repeatedly to replace only 2nd & 5th time repeated statements (ex: This is UNIX forum) with another statement ( UNIX forum threads in Shell programming) with out modifying 1st,3,4th repeated statements. I am planning to do... (2 Replies)
Discussion started by: watsup
2 Replies
4. Shell Programming and Scripting
Hi all
I am trying to get my head around doing the following....
I have an input field that could contain either a number a blank field or a whitespace field.
What I want to do is delete a 0 (zero) if it's on its own or leading the number.
So:-
\t0 delete the zero
0 delete the... (8 Replies)
Discussion started by: Bashingaway
8 Replies
5. Shell Programming and Scripting
Hi All,
Was wondering how I can do the following....
I have a String as follows
"ACCTRL000005022RRWDKKEEDKDD...."
This string can be in a file called tail.out or in a Variable called $VAR2
Now I have another variable called $VAR1="000004785" (9 bytes long), I need the content of... (5 Replies)
Discussion started by: mohullah
5 Replies
6. Shell Programming and Scripting
I am a newbie and would like some help with the following -
Trying to search fileA for a string similar to -
AS11000022010 30.4 31.7 43.7 53.8 60.5 71.1 75.2 74.7 66.9 56.6 42.7 32.5 53.3
I then want to replace that string with a string from fileB - ... (5 Replies)
Discussion started by: ncwxpanther
5 Replies
7. Shell Programming and Scripting
Hi there,
A total sed noob here. Is there a way using sed to delete everything before a character AND after another character on each line in a file? The deletion should also delete the indicating characters(here: an opening and a closing parenthesis).
The original file would look like... (3 Replies)
Discussion started by: bnbsd
3 Replies
8. Shell Programming and Scripting
Hi,
Anyone can help using SED searches a character string for a specified delimiter character, and returns a leading or trailing space/blank.
Text file :
"1"|"ExternalClassDEA519CF5"|"Art1"
"2"|"ExternalClass563EA516C"|"Art3"
"3"|"ExternalClass305ED16B8"|"Art9"
...
...
... (2 Replies)
Discussion started by: fspalero
2 Replies
9. Shell Programming and Scripting
Hello is it possible with awk or sed to replace any white space with the previous line characters in the same position?
I am asking this because the file I have doesn't always follow a pattern.
For example the file I have is the result of a command to obtain windows ACLs:
icacls C:\ /t... (5 Replies)
Discussion started by: nakaedu
5 Replies
10. Shell Programming and Scripting
I have a csv dataset like this :
C,rs18768
G,rs13785
GA,rs1065
G,rs1801279
T,rs9274407
A,rs730012
I'm thinking of use like awk, sed to covert the dataset to this format: (if it's two character, then keep the same)
CC,rs18768
GG,rs13785
GA,rs1065
GG,rs1801279
TT,rs9274407... (7 Replies)
Discussion started by: nengcheng
7 Replies
while(n) Tcl Built-In Commands while(n)
__________________________________________________________________________________________________________________________________________________
NAME
while - Execute script repeatedly as long as a condition is met
SYNOPSIS
while test body
_________________________________________________________________
DESCRIPTION
The while command evaluates test as an expression (in the same way that expr evaluates its argument). The value of the expression must a
proper boolean value; if it is a true value then body is executed by passing it to the Tcl interpreter. Once body has been executed then
test is evaluated again, and the process repeats until eventually test evaluates to a false boolean value. Continue commands may be exe-
cuted inside body to terminate the current iteration of the loop, and break commands may be executed inside body to cause immediate termi-
nation of the while command. The while command always returns an empty string.
Note: test should almost always be enclosed in braces. If not, variable substitutions will be made before the while command starts execut-
ing, which means that variable changes made by the loop body will not be considered in the expression. This is likely to result in an
infinite loop. If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
ation), so changes in the variables will be visible. For an example, try the following script with and without the braces around $x<10:
set x 0
while {$x<10} {
puts "x is $x"
incr x
}
SEE ALSO
break(n), continue(n), for(n), foreach(n)
KEYWORDS
boolean value, loop, test, while
Tcl while(n)