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)
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)
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)
Hi
I have a data file 'File2' consisting of 105670 lines. I want to copy and paste 17928 lines from 'File1' to 'File2' but I want to place it in between lines 21 and 17950 of 'File2'. How do I do it in awk?
For example-
File A has 5 lines
X
Y
1 2 3
4 5 6
7 8 9
and File B has
A
b... (1 Reply)
Hi
I have a data file 'File2' consisting of 105670 lines. I want to copy and paste 17928 lines from 'File1' to 'File2' but I want to place it in between lines 21 and 17950 of 'File2'. How do I do it in awk?
For example-
File A has 5 lines
X
Y
1 2 3
4 5 6
7 8 9
and File B has
A
b... (1 Reply)
Discussion started by: ananyob
1 Replies
LEARN ABOUT OSX
cat
CAT(1) BSD General Commands Manual CAT(1)NAME
cat -- concatenate and print files
SYNOPSIS
cat [-benstuv] [file ...]
DESCRIPTION
The cat utility reads files sequentially, writing them to the standard output. The file operands are processed in command-line order. If
file is a single dash ('-') or absent, cat reads from the standard input. If file is a UNIX domain socket, cat connects to it and then reads
it until EOF. This complements the UNIX domain binding capability available in inetd(8).
The options are as follows:
-b Number the non-blank output lines, starting at 1.
-e Display non-printing characters (see the -v option), and display a dollar sign ('$') at the end of each line.
-n Number the output lines, starting at 1.
-s Squeeze multiple adjacent empty lines, causing the output to be single spaced.
-t Display non-printing characters (see the -v option), and display tab characters as '^I'.
-u Disable output buffering.
-v Display non-printing characters so they are visible. Control characters print as '^X' for control-X; the delete character (octal
0177) prints as '^?'. Non-ASCII characters (with the high bit set) are printed as 'M-' (for meta) followed by the character for the
low 7 bits.
EXIT STATUS
The cat utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
The command:
cat file1
will print the contents of file1 to the standard output.
The command:
cat file1 file2 > file3
will sequentially print the contents of file1 and file2 to the file file3, truncating file3 if it already exists. See the manual page for
your shell (i.e., sh(1)) for more information on redirection.
The command:
cat file1 - file2 - file3
will print the contents of file1, print data it receives from the standard input until it receives an EOF ('^D') character, print the con-
tents of file2, read and output contents of the standard input again, then finally output the contents of file3. Note that if the standard
input referred to a file, the second dash on the command-line would have no effect, since the entire contents of the file would have already
been read and printed by cat when it encountered the first '-' operand.
SEE ALSO head(1), more(1), pr(1), sh(1), tail(1), vis(1), zcat(1), setbuf(3)
Rob Pike, "UNIX Style, or cat -v Considered Harmful", USENIX Summer Conference Proceedings, 1983.
STANDARDS
The cat utility is compliant with the IEEE Std 1003.2-1992 (``POSIX.2'') specification.
The flags [-benstv] are extensions to the specification.
HISTORY
A cat utility appeared in Version 1 AT&T UNIX. Dennis Ritchie designed and wrote the first man page. It appears to have been cat(1).
BUGS
Because of the shell language mechanism used to perform output redirection, the command ``cat file1 file2 > file1'' will cause the original
data in file1 to be destroyed!
The cat utility does not recognize multibyte characters when the -t or -v option is in effect.
BSD March 21, 2004 BSD