File Replace String activity The File Replace String activity finds and replaces a string in a file on a Linux or UNIX computer. Input variables Table 1. File replace string input variables Field Description Hostname Hostname or IP address of destination server for SSH activity. Directory Name of the working directory. File Name of the file in which the string is to be replaced. Find Pattern A regular expression of the text to replace Replace String The replacement string for the text found by the expression in the Find Pattern field. Options Select whether to replace only the first occurrence of the string or all occurrences.