tit:replace
type:$type_both
syntax:!replace [internal] ``s1'' by ``s2'' in ``string''\
!replace ``obj'' ``ident'' by ``s'' in ``string''
mean:String manipulation. <p>\
Under the first syntax, variable substitution is first done on ``string''.\
Then all occurences of substring ``s1'' are replaced by ``s2''. <br/>\
When the keyword ``internal'' is absent, the Linux utility ``sed'' is called to make the replacements,\
therefore regular expressions are accepted in ``s1'' and ``s2''.\
Please refer to the man page of ``sed'' for details. </p><p>\
Under the second syntax, ``obj'' can be ``char'', ``word'', ``item'' or ``line''.\
Then the word, item or line identified by ``ident'' in ``string'' is replaced\
by ``s'', after variable substitutions. <br/>\
``ident'' can be a string, in this case all objects (words, items or lines) matching ``ident'' \
will be replaced. It can also be a number (positive or negative integer ``n''), preceded\
by the word ``number''. In this case the object number ``n'' will be replaced.\
(In the case where n<0, it is the last -n th object which is replaced.)\
</p>