sed '1d;$d' filename

delete first and last line from file

deletes first and last line from file either empty or not.

By: 0verlord
2012-01-30 22:45:47

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    print 'g/'delete this line'/delete\nwq' | ex file.txt
    mph · 2009-07-20 19:15:29 3
  • Using sed to extract lines in a text file If you write bash scripts a lot, you are bound to run into a situation where you want to extract some lines from a file. Yesterday, I needed to extract the first line of a file, say named somefile.txt. cat somefile.txt Line 1 Line 2 Line 3 Line 4 This specific task can be easily done with this: head -1 somefile.txt Line 1 For a more complicated task, like extract the second to third lines of a file. head is inadequate. So, let's try extracting lines using sed: the stream editor. My first attempt uses the p sed command (for print): sed 1p somefile.txt Line 1 Line 1 Line 2 Line 3 Line 4 Note that it prints the whole file, with the first line printed twice. Why? The default output behavior is to print every line of the input file stream. The explicit 1p command just tells it to print the first line .... again. To fix it, you need to suppress the default output (using -n), making explicit prints the only way to print to default output. sed -n 1p somefile.txt Line 1 Alternatively, you can tell sed to delete all but the first line. sed '1!d' somefile.txt Line 1 '1!d' means if a line is not(!) the first line, delete. Note that the single quotes are necessary. Otherwise, the !d will bring back the last command you executed that starts with the letter d. To extract a range of lines, say lines 2 to 4, you can execute either of the following: sed -n 2,4p somefile.txt sed '2,4!d' somefile.txt Note that the comma specifies a range (from the line before the comma to the line after). What if the lines you want to extract are not in sequence, say lines 1 to 2, and line 4? sed -n -e 1,2p -e 4p somefile.txt Line 1 Line 2 Line 4 Show Sample Output

    sed -n -e 1186,1210p
    evandrix · 2011-06-04 10:53:46 0
  • Instead, install apt-get install secure-delete and you can use: -- srm to delete file and directory on hard disk -- smem to delete file in RAM -- sfill to delete "free space" on hard disk -- sswap to delete all data from swap

    shred -u -z -n 17 rubricasegreta.txt
    0disse0 · 2010-01-31 15:24:54 0
  • This command is recursive and will delete in all directories in ".". It will find and delete all files not specified with ! -name "pattern". In this case it's file extensions. -type f means it will only find files and not directories. Finally the -delete flag ask find to delete what it matches. You can test the command by running it first without delete and it will list the files it will delete when you run it. Show Sample Output

    find . -type f ! -name "*.foo" -name "*.bar" -delete
    sh1mmer · 2010-10-07 20:17:38 0
  • i wanted to delete all duplicate lines from .bash_history and keep the order of the other lines. the command cat's the file and adds line numbers, then sorts by the second column. afterwards uniq omits repeated lines, but skips the first field (the line number). then it sorts by the line numbers and at the end cuts the numbers off.

    cat -n <file> | sort -k 2 | uniq -f 1 | sort -n | cut -f 2-
    fpunktk · 2010-01-21 18:55:58 3
  • Use sed to remove the last line of a file only if it is empty.

    sed '${/^$/d}' file
    moogmusic · 2012-01-25 14:07:55 1

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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