Editing commands from the history file
Suppose that you have a sequence of source files named file1.c, file2.c, file3.c, and so on that you want to compile with similar c89 commands. This situation is a little different from the one discussed in the previous topic. You do not want to rerun the same command for each file; the command has the same form each time, but you have to specify in a new file name each time.
r old_string=new_string command
runs a previous command but replaces the first occurrence of the old string
with the new string. For example, suppose you compile file1.c with:
c89 options file1.c
Then
the command:
r file1=file2 c89
tells the shell to search
back for the most recent c89 command and change file1 to file2. The shell makes this change,
and then displays and runs the modified command.
r file2=file3 c89
performs
the same kind of operation, changing file2 in
the previous command to file3 and then going
ahead with the compilation. This saves you the trouble of retyping
all the options for the command.history="fc –l"
The history command is actually
a predefined alias for the fc command
with the –l option. The fc command is used
to display and edit commands in the history file. Generally, it is
easier to remember to type history, so the shell predefines
this alias.If you have displayed the predefined aliases, you probably noticed that r is also a predefined alias. It also stands for a version of the fc command. As with history, the r alias was created because it's easier to use and read than the straight fc command. For full details about fc, see the fc command description in z/OS UNIX System Services Command Reference.