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Full Discussion: Inputting text to a specific line of a file
Top Forums UNIX for Dummies Questions & Answers Inputting text to a specific line of a file Post 302434264 by DeCoTwc on Friday 2nd of July 2010 03:21:03 AM
Old 07-02-2010
Just a crappy shell solution. I don't know if this is what you were looking for. It adds a line before the line that says last


Code:
(03:19:41\[D@DeCoBox15)
[~]$ cat file
first
second
third
fourth
fith
last

(03:19:45\[D@DeCoBox15)
[~]$ type insert
insert is a function
insert ()
{
    tac $1 | while read line; do
        if [[ $line == "last" ]]; then
            echo $line;
            echo "$2";
        else
            echo $line;
        fi;
    done | tac
}

(03:19:48\[D@DeCoBox15)
[~]$ insert file "look ma, new text"
first
second
third
fourth
fith
look ma, new text
last


I just put it in a function so type would auto format it from the one-liner I wrote it as.
 

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LEARN ABOUT REDHAT

tac

TAC(1)									FSF								    TAC(1)

NAME

       tac - concatenate and print files in reverse

SYNOPSIS

       tac [OPTION]... [FILE]...

DESCRIPTION

       Write each FILE to standard output, last line first.  With no FILE, or when FILE is -, read standard input.

       Mandatory arguments to long options are mandatory for short options too.

       -b, --before
	      attach the separator before instead of after

       -r, --regex
	      interpret the separator as a regular expression

       -s, --separator=STRING
	      use STRING as the separator instead of newline

       --help display this help and exit

       --version
	      output version information and exit

AUTHOR

       Written by Jay Lepreau and David MacKenzie.

REPORTING BUGS

       Report bugs to <bug-coreutils@gnu.org>.

COPYRIGHT

       Copyright (C) 2002 Free Software Foundation, Inc.
       This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
       LAR PURPOSE.

SEE ALSO

       The full documentation for tac is maintained as a Texinfo manual.  If the info and tac programs are properly installed at  your	site,  the
       command

	      info tac

       should give you access to the complete manual.

tac (coreutils) 4.5.3						   February 2003							    TAC(1)
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