问题:

Sample file : abc.ksh

echo "This is a sample file." >> mno.txt
echo "\nThis line has new line char." >> mno.txt

I want

echo "\nThis line has new line char." >> mno.txt

as output.

回答1:

Use -F to match fixed strings:

$ grep -F "\n" file
echo "\nThis line has new line char." >> mno.txt

From man grep:

-F, --fixed-strings

Interpret PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched. (-F is specified by POSIX.)

回答2:

Easiest way is using REGEX:

grep "$" filename  # this will match all lines ending with "\n" (often all lines)
grep "PATTERN$"    # this will match all lines ending with "PATTERN\n"

In REGEX language, $ means EOL (end of line), so it will often match "\n" (cause is very common as the end of line).

WARNING: be careful to use versions of grep that support REGEX!.

回答3:

Simply escape the backslash with another backslash and put the regex in single quotes so the shell does pass it to grep without handling the backslashes itself: