C Language, printf/scanf format character(s) for 64 bit ints ??

printf/scanf format character(s) for 64 bit ints ??

Author	Message
Marv Grah #1 / 5	printf/scanf format character(s) for 64 bit ints ?? We are adding a 64 bit integer type to our C compiler. If your C compiler andles 64-bit integers, what do you put in the format string for scanf/printf to read and print them? I don't have manuals for other systems readily available. I know that Convex uses %ll, but I would prefer a single letter: maybe %L. Please let me hear your facts and/or opinions. AT&T GIS Dept. 789 ...!uunet!ncrcom!ncrcae!grok162!marv 3325 Platt Springs Rd. phone: 1 803 939 5501 W. Columbia, SC 29170-2203 fax: 1 803 939 7317 -- AT&T GIS Dept. 789 ...!uunet!ncrcom!ncrcae!grok162!marv 3325 Platt Springs Rd. phone: 1 803 939 5501 W. Columbia, SC 29170-2203 fax: 1 803 939 7317
Mon, 19 Aug 1996 04:50:13 GMT

t_akrish.. #2 / 5	printf/scanf format character(s) for 64 bit ints ?? Quote: >We are adding a 64 bit integer type to our C compiler. If your C compiler >andles 64-bit integers, what do you put in the format string for scanf/printf >to read and print them? >I don't have manuals for other systems readily available. I know that >Convex uses %ll, but I would prefer a single letter: maybe %L. From ISO C 7.13 (Future library directions) - 7.13.6 Input/output <stdio.h> : "Lowercase letters may be added to the conversion specifiers in fprintf and fscanf. Other characters may be used as extensions." It looks as if the committee wanted to reserve the lowercase letters for extra conversion specifications to be put in future revisions. So, for current implementations, uppercase letters and _ might be a better choice. ------- /* Ajoy Krishnan T, Senior S/W Engineer, Hughes Software Systems, New Delhi - 19, India.
Mon, 26 Aug 1996 12:04:00 GMT

Dan P #3 / 5	printf/scanf format character(s) for 64 bit ints ?? Quote: >We are adding a 64 bit integer type to our C compiler. If your C compiler >andles 64-bit integers, what do you put in the format string for scanf/printf >to read and print them? "%l" on the DEC Alpha cc. Quote: >I don't have manuals for other systems readily available. I know that >Convex uses %ll, but I would prefer a single letter: maybe %L. >Please let me hear your facts and/or opinions. Make the 64 bit integer type "long" and you don't have to invent anything. Just my $0.02, Dan -- Dan Pop CERN, CN Division Mail: CERN - PPE, Bat. 31 R-004, CH-1211 Geneve 23, Switzerland
Mon, 26 Aug 1996 17:49:02 GMT

Morgan Gregory La #4 / 5	printf/scanf format character(s) for 64 bit ints ?? : Make the 64 bit integer type "long" and you don't have to invent : anything. That wuld create porability problems, then everyone else that wanted to use any of the source for that compiler would have to have a double long (in most cases) to accomodate for the 64 bits. The same thing can occure when going from UNIX to DOS, and int just isn't the same thing anymore, if you are lucky there will be the ocasional programmer that will take this into account and instead of just saying 'int i', will say 'long int i', this dosen't mean much for the unix os but for the dos os it means a world of difference, just like going the other way 'short int i' can be a great deal of help (ie dos to unix). Though I'll grant you this the 16 bit int and 32 bit int (almost) are becoming a dieing breed they don't need to be totally ignored. I can't recommend a format specifier for the original poster since I don't run into the need for such a thing just take into consideration that C code goes between platforms all the time. ------------------------------------------------------------------------- Student programmers have (*NULL) free time... -------------------------------------------------------------------------
Tue, 27 Aug 1996 09:24:50 GMT

Dan P #5 / 5	printf/scanf format character(s) for 64 bit ints ?? Quote: >: Make the 64 bit integer type "long" and you don't have to invent >: anything. > That wuld create porability problems, then everyone else that Yes, if the code is not portable, this will certainly cause portability problems :-) Quote: >wanted to use any of the source for that compiler would have to have >a double long (in most cases) to accomodate for the 64 bits. The same >thing can occure when going from UNIX to DOS, and int just isn't the >same thing anymore, if you are lucky there will be the ocasional >programmer that will take this into account and instead of just saying >'int i', will say 'long int i', this dosen't mean much for the unix >os but for the dos os it means a world of difference, just like going >the other way 'short int i' can be a great deal of help (ie dos to unix). >Though I'll grant you this the 16 bit int and 32 bit int (almost) are >becoming a dieing breed they don't need to be totally ignored. I can't >recommend a format specifier for the original poster since I don't run >into the need for such a thing just take into consideration that C code >goes between platforms all the time. C code which is not _broken_ goes between platforms all the time without any problems, no matter what the sizes of the integer types are. The standard specifies the minimum number of bits for each integer type. If a program relies on a greater number of bits than the one guaranteed, that program is non-portable and it can be considered broken from the portability point of vue. The idea to design compilers in such a way that non-portable code can be ported doesn't make much sense for me. If a program is broken, you don't fix the compiler, although the reverse happens from time to time :-) Dan -- Dan Pop CERN, CN Division Mail: CERN - PPE, Bat. 31 R-004, CH-1211 Geneve 23, Switzerland
Tue, 27 Aug 1996 16:48:09 GMT

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