The file.txt is the input file the grep command uses to search for empty lines. The > is the redirection operator, which redirected the output of the grep command to the outFile.txt file. If it already exists, the> operator will overwrite the outFile.txt file. You can also use >> if...
Method 1: Run the sed Command to Remove Empty Lines in Bash In our first solution, we will use the sed command to remove the empty lines in Bash from the file. The sed command is used to do simple text changes. The stream editor sed can remove blank lines from files, as seen below...
$ unset x $ showvar $x is not set $ x=3 $ showvar $x is not set $ export x $ showvar $x = 3 $ x= ## in bash, reassignment doesn't remove a variable from the environment $ showvar $x is set but empty 注意 showvar不是一个 bash 命令,而是一个如清单 5-1 所示的脚本,...
# Remove empty lines from the text file "temp.txt" and save the result to a temporary file grep -v '^$' temp.txt > temp_no_empty_lines.txt # Replace the original file with the one without empty lines mv temp_no_empty_lines.txt temp.txt # Check if empty lines were successfully r...
-k file 若文件存在且设置了"sticky"位的值 -p file 若文件存在且为一已命名管道,则为真 -r file 若文件存在且可读,则为真 -s file 若文件存在且其大小大于零,则为真 -u file 若文件存在且设置了SUID位,则为真 -w file 若文件存在且可写,则为真 ...
# Usage: remove_array_dups "array" declare -A tmp_array for i in "$@"; do [[ $i ]] && IFS=" " tmp_array["${i:- }"]=1 done printf '%s\n' "${!tmp_array[@]}" } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 用法示例: ...
# Usage: remove_array_dups "array" declare -A tmp_array for i in "$@"; do [[ $i ]] && IFS=" " tmp_array["${i:- }"]=1 done printf '%s\n' "${!tmp_array[@]}" } 用法示例: $ remove_array_dups 1 1 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 5 ...
Like SPACE, but scrolls a full screenful, even if it reaches end-of-file in the process. ENTER or RETURN or ^N or e or ^E or j or ^J Scroll forward N lines, default 1. The entire N lines are displayed, even if N is more than the screen size. ...
{ action }: The action or series of commands to execute on lines that match the pattern. input-file: The file or data source to process. If omitted,awkreads from standard input (usually provided via a pipeline or redirection). Here’s how we can use theawkcommand to remove newline char...
--init-file file --rcfile file Execute commands from file instead of the standard per- sonal initialization file ~/.bashrc if the shell is interactive (see INVOCATION below). --login Equivalent to -l. --noediting Do not use the GNU readline library to read command lines when the shell ...