I have a problem that I want to insert and delete some chars in the middle of a file. fopen() and fdopen() just allow to append at the end.
Is there any simple method or existing library that allow these actions? Thanks in advance.:confused: (7 Replies)
I'm trying to insert a single character at position 11 in everyline of a file.
My input file looks like this:
456781 ~Y~12345
456782 ~N~12300
and I want my output to look like this:
45678~1 ~Y~12345
45678~2 ~N~12300
I tried the following awk code, but it's not working:... (3 Replies)
Script 1
Pre-requisites
Create a file with x amount of lines in it, the content of your choice.
Write a script that takes two arguments. The first being a line of text, the second being your newly created file. The script should take the first argument and insert it into the very top (the... (3 Replies)
I wrote a script like
#!/bin/bash
echo $1 > temp
cat $2 >> temp
mv temp $2
now I have problem appending the above script(only using bash shell) so that it now inserts the first argument into the middle of the file.
I have tried using $(('wc -l < file' / 2 ))
but invain so could any one... (4 Replies)
how to insert one file into another file not by concatenating as usual done.
file1
A B
C D
E F
G H
I J
K L
file2
23455
33444
33334
33345
Output shud be
23455
A B
C D (4 Replies)
Hey guys, how do we take a line of text as an argument from a user and then insert it in the middle of a file irrespective of the number of lines in the file. I am trying to do this without SED or AWK. Inserting it in the beginning and at the end is easy, but i am trying to accomplish inserting... (6 Replies)
Hi,
So far i've made a script that takes two argument, 1st is the contents and the 2nd is the named file. At the moment i've managed to insert new contents as a new line at the top, but i want to ask how can you insert contents in the middle of the file?
Source Code
#!/bin/bash
#Write... (3 Replies)
Hi all,
How can i display the middle line of a file using a single line command? (6 Replies)
Discussion started by: Lakme Pemmaiah
6 Replies
LEARN ABOUT PLAN9
regexp
REGEXP(6) Games Manual REGEXP(6)NAME
regexp - regular expression notation
DESCRIPTION
A regular expression specifies a set of strings of characters. A member of this set of strings is said to be matched by the regular
expression. In many applications a delimiter character, commonly bounds a regular expression. In the following specification for regular
expressions the word `character' means any character (rune) but newline.
The syntax for a regular expression e0 is
e3: literal | charclass | '.' | '^' | '$' | '(' e0 ')'
e2: e3
| e2 REP
REP: '*' | '+' | '?'
e1: e2
| e1 e2
e0: e1
| e0 '|' e1
A literal is any non-metacharacter, or a metacharacter (one of .*+?[]()|^$), or the delimiter preceded by
A charclass is a nonempty string s bracketed [s] (or [^s]); it matches any character in (or not in) s. A negated character class never
matches newline. A substring a-b, with a and b in ascending order, stands for the inclusive range of characters between a and b. In s,
the metacharacters an initial and the regular expression delimiter must be preceded by a other metacharacters have no special meaning and
may appear unescaped.
A matches any character.
A matches the beginning of a line; matches the end of the line.
The REP operators match zero or more (*), one or more (+), zero or one (?), instances respectively of the preceding regular expression e2.
A concatenated regular expression, e1e2, matches a match to e1 followed by a match to e2.
An alternative regular expression, e0|e1, matches either a match to e0 or a match to e1.
A match to any part of a regular expression extends as far as possible without preventing a match to the remainder of the regular expres-
sion.
SEE ALSO awk(1), ed(1), sam(1), sed(1), regexp(2)REGEXP(6)