File I/O

[Mike Wahler]

...

argc = 6; and argv[] = { "myprog", "i", "am", "a", "c", "freak" };

Not necessarily. The first element could be "\0";

True, but I think it's more likely to be "" than "\0", although I can't
really justify the statement in any objective fashion. <g>

Sloppy presentation on my part. I did mean an 'empty string',
but was trying to be clearer by inserting the '\0' character.
Not the first time one of my attempts at clarity resulted
in the opposite.

-Mike

 

[those who know me have no need of my name]

in comp.lang.c i read:

A minor point, which is now easily controlled (and seen). If the
user enters the same name for argv[1] and argv[2] opening the
'out' file could destroy the prospective 'in' file. Handling the
'in' file first usually gives some added assurance, because most
systems will refuse to open for write a file that is already open
for read.

`most systems'? well, some at least. comparing the filenames is about the
best you can do in a totally portable program (even this has flaws), only
then hoping that the system won't truncate a file already open for reading.

 

[Bill Cunningham]

ls -l



Jan Engelhardt

In a UNIX or LINUX environment a directory will be listed. At least on my
linux OSs it's ls -la.

Bill

 

[Mike Wahler]

In a UNIX or LINUX environment a directory will be listed. At least on my
linux OSs it's ls -la.

I think you've missed the point. In an 'ls' written in C,
That invocation would cause argc to have a value of 2,
argv[0] would be either "" or "ls", and argv[1] would
be "-l". IOW argc/argv is how the program retrieves
user supplied parameters.

-Mike

 

[Bill Cunningham]

I think you've missed the point. In an 'ls' written in C,

That invocation would cause argc to have a value of 2,
argv[0] would be either "" or "ls", and argv[1] would
be "-l". IOW argc/argv is how the program retrieves
user supplied parameters.

-Mike

I see.