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The sed command will, by default, print the pattern space at the end of each cycle. However, in this example, we only want to ask sed to print the lines we need. Therefore, we've used the -n option to prevent the sed command from printing the pattern space. Instead, we'll control the output using the p command.
Awk works by scanning through each line of text (or record) in the file and carrying out any instructions you tell it on that line. In awk we access fields using syntax like: $1 or $2. $1 indicates that you are referring to the first field or first column.
sed and awk are two different executables. To use them together, you will have to "pipe" the output of one as input of another. For that matter you can pipe output of any process to input of any other process.
Use awk with a flag to trigger the print when necessary:
$ awk '/abc/{flag=1;next}/mno/{flag=0}flag' file
def1
ghi1
jkl1
def2
ghi2
jkl2
How does this work?
/abc/ matches lines having this text, as well as /mno/ does. /abc/{flag=1;next} sets the flag when the text abc is found. Then, it skips the line. /mno/{flag=0} unsets the flag when the text mno is found.flag is a pattern with the default action, which is to print $0: if flag is equal 1 the line is printed.For a more detailed description and examples, together with cases when the patterns are either shown or not, see How to select lines between two patterns?.
Using sed:
sed -n -e '/^abc$/,/^mno$/{ /^abc$/d; /^mno$/d; p; }'
The -n option means do not print by default.
The pattern looks for lines containing just abc to just mno, and then executes the actions in the { ... }. The first action deletes the abc line; the second the mno line; and the p prints the remaining lines. You can relax the regexes as required. Any lines outside the range of abc..mno are simply not printed.
This might work for you (GNU sed):
sed '/^abc$/,/^mno$/{//!b};d' file
Delete all lines except for those between lines starting abc and mno
sed '/^abc$/,/^mno$/!d;//d' file
golfs two characters better than ppotong's {//!b};d
The empty forward slashes // mean: "reuse the last regular expression used". and the command does the same as the more understandable:
sed '/^abc$/,/^mno$/!d;/^abc$/d;/^mno$/d' file
This seems to be POSIX:
If an RE is empty (that is, no pattern is specified) sed shall behave as if the last RE used in the last command applied (either as an address or as part of a substitute command) was specified.
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