sed¶

stream editor (substitution)
NAME
    sed - stream editor (substitution)

SYNOPSIS
    sed s/regex/replacement/[g] [file]

DESCRIPTION
    Applies a single substitution command to each line of a file (or of
    standard input) and prints the result. Only the s/// command is
    supported. The left-hand side is a basic regex (the same dialect as
    grep: . * + ? ^ $); the replacement is literal text. Without the
    trailing g only the first match on a line is replaced. sed is a /bin
    program.

EXAMPLES
    sed s/foo/bar/ file      replace the first foo on each line
    sed s/foo/bar/g file     replace every foo
    cmd | sed s/x/y/         substitute on a pipe

SEE ALSO
    grep, cat