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How to remove newline character if it is the only character in the entire file.?

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Top Forums Shell Programming and Scripting How to remove newline character if it is the only character in the entire file.?
# 8  
Old 01-27-2019
Even if your system doesn't have the stat command, you could also use:
Code:
[ $(wc -c < "$file") -eq 1 ] && > "$file"

The command:
Code:
wc -c < "$file"

prints the number of bytes found on its standard input (in this case the contents of the file you're interested in) and if that is equal to 1, the redirection recreates the file as an empty file.
# 9  
Old 01-28-2019
In contrast to wc, grep with -l or -q option stops reading the input when a match has occurred.
In this case a
Code:
grep -q . file

(stop if any character is met) seems sufficient.
Because grep returns an exit status it becomes quite simple:
Code:
file=myfile.log
grep -q . "$file" || >"$file"

Note that -q is not portable. If this is an issue, use the -l option and suppress output.
Code:
file=myfile.log
grep -l . "$file" >/dev/null || >"$file"

Last edited by MadeInGermany; 01-28-2019 at 10:38 AM..
These 3 Users Gave Thanks to MadeInGermany For This Post:
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