File operations

Search/replace in (multiple) files

Problem

Replace Alice with Bob in all files in directory *

sed -i 's/Alice/Bob/g' *

Command explanation

• sed is the Stream EDitor command tool which can be used to manipulate file contents (among other things)
• -i is the option for edit file in place. Without this a new file is generated as the result of the command.
  • Giving the command a suffix, e.g. -i_backup, will make backup files in case you need to undo changes.
• s/Alice/Bob/g is the substitute command that replaces all instances of Alice with Bob
  • s is the substitute command
  • / is the separator between the different command fragments. You can use other special characters as separators if needed
  • Alice is the search term. This can also be a regex
  • Bob is the replacement. This can also be a regex
  • g is regex for global, meaning replace all instances. Omit for only replacing the first occurrence
• * is the file(s) to affect.