Here, the null string is replaced by ‘ New Text‘.
The '1' at the beginning signifies that sed should consider the null string at beginning of line 1 and the 's' is a sed command, to replace a string.
To add new text on the existing line, run: $ sed -i '1s/^/New Text/' filenameīasically, the exponent symbol (‘^’) signifies a null string. Insert Text New Line at Beginning of FileĪgain, this is adding the new content on a new line at the beginning. $ sed -i '1i Introduction' samplefile.txt The string ‘1i New Text’ means: ‘insert’ the string ‘New Text’ on the ‘1st’ line. Without it, sed automatically creates a copy of the file and performs all modifications on the copy. The -i argument tells sed to modify the file itself. Run the following to insert text on a new line at the beginning. We will be using particular features of sed to add text to the beginning of a file. Sed is a complex command with a lot of options to edit files in various ways. Sed (short for ‘ Stream Editor‘) is a command-line editor in Linux, that is used to perform operations like writing text to a file, find and replace, etc. Add Text to First Line of File Using sed Command Hence there might be a scenario when ‘ samplefile.txt’ is a file containing a humongous amount of data, and the variable fails to store all of it. Note that although Bash or many other shells do not have a limit on the size of a variable, however, the size may be limited based on the environment and system configuration. To add the text at the beginning of the existing first line, use the -n argument of echo. $ x=`echo "Name: John" cat samplefile.txt`Īs you can see above, the new text was added on a new line at the beginning of the file. Then, we simply output the variable and redirect it to the same file. This can be done as follows: $ x=`echo "New Text" cat filename`īasically, we are combining the new text and existing contents of the file, and storing the new contents in a variable. We can thus pass the new text to be added to echo, pass the file to a cat, combine and write the output to the file.
Add Text to Beginning of File Using echo and cat CommandsĪs you might know, the echo command prints whatever is passed as the argument to the output, whereas the cat command prints the contents of a file to the output. You can simply copy a file called ‘ file1’ to another file called ‘ file1_bkp’ and then append the text to the original, i.e. This way if any error occurs while using the commands, we can always restore the backup file. Note: It is a good approach to first backup the original file and then append the new text to the original file.
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