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... (2 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)
I have tried
sed '/6/a text_to_inserted' file > newfile
but this inserts test_to_insert at random places in file and i want it in specific location, which is line 6.
can anyone help.... (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)
Discussion started by: zen10
3 Replies
LEARN ABOUT OPENDARWIN
tail
TAIL(1) BSD General Commands Manual TAIL(1)NAME
tail -- display the last part of a file
SYNOPSIS
tail [-F | -f | -r] [-b number | -c number | -n number] [file ...]
DESCRIPTION
The tail utility displays the contents of file or, by default, its standard input, to the standard output.
The display begins at a byte, line or 512-byte block location in the input. Numbers having a leading plus (``+'') sign are relative to the
beginning of the input, for example, ``-c +2'' starts the display at the second byte of the input. Numbers having a leading minus (``-'')
sign or no explicit sign are relative to the end of the input, for example, ``-n 2'' displays the last two lines of the input. The default
starting location is ``-n 10'', or the last 10 lines of the input.
The options are as follows:
-b number
The location is number 512-byte blocks.
-c number
The location is number bytes.
-f The -f option causes tail to not stop when end of file is reached, but rather to wait for additional data to be appended to the
input. The -f option is ignored if the standard input is a pipe, but not if it is a FIFO.
-F The -F option implies the -f option, but tail will also check to see if the file being followed has been renamed or rotated. The
file is closed and reopened when tail detects that the filename being read from has a new inode number. The -F option is ignored if
reading from standard input rather than a file.
-n number
The location is number lines.
-r The -r option causes the input to be displayed in reverse order, by line. Additionally, this option changes the meaning of the -b,
-c and -n options. When the -r option is specified, these options specify the number of bytes, lines or 512-byte blocks to display,
instead of the bytes, lines or blocks from the beginning or end of the input from which to begin the display. The default for the -r
option is to display all of the input.
If more than a single file is specified, each file is preceded by a header consisting of the string ``==> XXX <=='' where ``XXX'' is the name
of the file.
DIAGNOSTICS
The tail utility exits 0 on success, and >0 if an error occurs.
SEE ALSO cat(1), head(1), sed(1)STANDARDS
The tail utility is expected to be a superset of the IEEE Std 1003.2-1992 (``POSIX.2'') specification. In particular, the -F, -b and -r
options are extensions to that standard.
The historic command line syntax of tail is supported by this implementation. The only difference between this implementation and historic
versions of tail, once the command line syntax translation has been done, is that the -b, -c and -n options modify the -r option, i.e. ``-r
-c 4'' displays the last 4 characters of the last line of the input, while the historic tail (using the historic syntax ``-4cr'') would
ignore the -c option and display the last 4 lines of the input.
HISTORY
A tail command appeared in PWB UNIX.
BSD June 6, 1993 BSD