Fvstot, Fvttos - convert C structure to/from target record type
#include <stdio.h> #include "fml.h" long Fvstot(char *cstruct, char *trecord, long treclen, char *viewname) long Fvttos(char *cstruct, char *trecord, char *viewname) #include "fml32.h" int Fvstot32(char *cstruct, char *trecord, long treclen, char *viewname) int Fvttos32(char *cstruct, char *trecord, char *viewname) int Fcodeset(char *translation_table)
The Fvstot() function transfers data from a C structure to a target record type. The Fvttos() function transfers data from a target record to a C structure. trecord is a pointer to the target record. cstruct is a pointer to a C structure. viewname is a pointer to the name of a compiled view description. The VIEWDIR and VIEWFILES are used to find the directory and file containing the compiled view description.
Fvttos32 and Fvstot32 are used with 32-bit VIEWS.
To convert from an FML buffer to a target record, first call Fvftos to convert the FML buffer to a C structure, and call Fvstot to convert to a target record. To convert from a target record to an FML buffer, first call Fvttos to convert to a C structure and then call Fvstof to convert the structure to an FML buffer.
The default target is IBM/370 COBOL records. The default data
conversion is done based on the following table.
| Struct | Record |
| float | COMP-1 |
| double | COMP-2 |
| long | S9(9) COMP |
| short | S9(4) COMP |
| int | S9(9) COMP or S9(4) COMP |
| dec_t(m, n) | S9(2*m-(n+1))V9(n)COMP-3 |
| ASCII char | EBCDIC char |
| ASCII string | EBCDIC string |
| carray | character array |
No filler bytes are provided between fields in the IBM/370 record. The COBOL SYNC clause should not be specified for any data items that are a part of the structure corresponding to the view.
An integer field is converted to either a four or two-byte integer depending on the size of integers on the machine on which the conversion is done.
A string field in the view must be terminated with a null when converting to/from the IBM/370 format.
The data in a carray field is passed unchanged; no data translation is performed.
Packed decimals exist in the IBM/370 environment as two decimal digits packed into one byte with the low-order half byte used to store the sign. The length of a packed decimal may be 1 to 16 bytes with storage available for 1 to 31 digits and a sign.
Packed decimals are supported in C structures using the dec_t field type. The dec_t field has a defined size consisting of two numbers separated by a comma. The number to the left of the comma is the total number of bytes that the decimal occupies. The number to the right is the number of digits to the right of the decimal point. The formula for conversion is:
dec_t(m, n) <=> S9(2*m-(n+1))V9(n)COMP-3
Decimal values may be converted to and from other data types (e.g., int, long, string, double, and float) using the functions described in decimal(3c).
The following table provides the hex values for default character conversion of ASCII (on the left) to/from EBCDIC (on the right).
| 00 00 |01 01 |02 02 |03 03 |04 37 |05 2d |06 2e |07 2f | | 08 16 |09 05 |0a 25 |0b 0b |0c 0c |0d 0d |0e 0e |0f 0f | | 10 10 |11 11 |12 12 |13 13 |14 3c |15 3d |16 32 |17 26 | | 18 18 |19 19 |1a 3f |1b 27 |1c 1c |1d 1d |1e 1e |1f 1f | | 20 40 |21 5a |22 7f |23 7b |24 5b |25 6c |26 50 |27 7d | | 28 4d |29 5d |2a 5c |2b 4e |2c 6b |2d 60 |2e 4b |2f 61 | | 30 f0 |31 f1 |32 f2 |33 f3 |34 f4 |35 f5 |36 f6 |37 f7 | | 38 f8 |39 f9 |3a 7a |3b 5e |3c 4c |3d 7e |3e 6e |3f 6f | | 40 7c |41 c1 |42 c2 |43 c3 |44 c4 |45 c5 |46 c6 |47 c7 | | 48 c8 |49 c9 |4a d1 |4b d2 |4c d3 |4d d4 |4e d5 |4f d6 | | 50 d7 |51 d8 |52 d9 |53 e2 |54 e3 |55 e4 |56 e5 |57 e6 | | 58 e7 |59 e8 |5a e9 |5b ad |5c e0 |5d bd |5e 5f |5f 6d | | 60 79 |61 81 |62 82 |63 83 |64 84 |65 85 |66 86 |67 87 | | 68 88 |69 89 |6a 91 |6b 92 |6c 93 |6d 94 |6e 95 |6f 96 | | 70 97 |71 98 |72 99 |73 a2 |74 a3 |75 a4 |76 a5 |77 a6 | | 78 a7 |79 a8 |7a a9 |7b c0 |7c 6a |7d d0 |7e a1 |7f 07 | | 80 20 |81 21 |82 22 |83 23 |84 24 |85 15 |86 06 |87 17 | | 88 28 |89 29 |8a 2a |8b 2b |8c 2c |8d 09 |8e 0a |8f 1b | | 90 30 |91 31 |92 1a |93 33 |94 34 |95 35 |96 36 |97 08 | | 98 38 |99 39 |9a 3a |9b 3b |9c 04 |9d 14 |9e 3e |9f e1 | | a0 41 |a1 42 |a2 43 |a3 44 |a4 45 |a5 46 |a6 47 |a7 48 | | a8 49 |a9 51 |aa 52 |ab 53 |ac 54 |ad 55 |ae 56 |af 57 | | b0 58 |b1 59 |b2 62 |b3 63 |b4 64 |b5 65 |b6 66 |b7 67 | | b8 68 |b9 69 |ba 70 |bb 71 |bc 72 |bd 73 |be 74 |bf 75 | | c0 76 |c1 77 |c2 78 |c3 80 |c4 8a |c5 8b |c6 8c |c7 8d | | c8 8e |c9 8f |ca 90 |cb 9a |cc 9b |cd 9c |ce 9d |cf 9e | | d0 9f |d1 a0 |d2 aa |d3 ab |d4 ac |d5 4a |d6 ae |d7 af | | d8 b0 |d9 b1 |da b2 |db b3 |dc b4 |dd b5 |de b6 |df b7 | | e0 b8 |e1 b9 |e2 ba |e3 bb |e4 bc |e5 4f |e6 be |e7 bf | | e8 ca |e9 cb |ea cc |eb cd |ec ce |ed cf |ee da |ef db | | f0 dc |f1 dd |f2 de |f3 df |f4 ea |f5 eb |f6 ec |f7 ed | | f8 ee |f9 ef |fa fa |fb fb |fc fc |fd fd |fe fe |ff ff | 1
An alternate character translation table can be used at run-time by calling Fcodeset(). The translation_table must point to 512 bytes of binary data. The first 256 bytes of data are interpreted as the ASCII to EBCDIC translation table. The second 256 bytes of data are interpreted as the EBCDIC to ASCII table. Any data after the 512th byte is ignored. If the pointer is NULL, the default translation is used.
On success, Fvstot returns the length of the target record and Fvttos returns the length of the C structure.
These functions return -1 on error and set Ferror to indicate the error condition.
Under the following conditions, Fvttos() fails and sets Ferror to:
VIEW test.v
VIEW test
#type cname fbname count flag size null
float float1 FLOAT1 1 - - 0.0
double double1 DOUBLE1 1 - - 0.0
long long1 LONG1 1 - - 0
short short1 SHORT1 1 - - 0
int int1 INT1 1 - - 0
dec_t dec1 DEC1 1 - 4,2 0
char char1 CHAR1 1 - - \0
string string1 STRING1 1 - 20 \0
carray carray1 CARRAY1 1 - 20 \0
END
Equivalent COBOL Record
02 OUTPUT-REC.
05 FLOAT1 USAGE IS COMP-1.
05 DOUBLE1 USAGE IS COMP-2.
05 LONG1 PIC S9(9) USAGE IS COMP.
05 SHORT1 PIC S9(4) USAGE IS COMP.
05 INT1 PIC S9(9) USAGE IS COMP.
05 DEC1 PIC S9(5)V9(2) COMP-3.
05 CHAR1 PIC X(01).
05 STRING1 PIC X(20).
05 CARRAY1 PIC X(20).
C Program
#include "test.h"
#include "decimal.h"
main()
{
struct test s1;
char data[100];
s1.float1 = 1.0;
s1.double1 = 2.0;
s1.long1 = 3;
s1.short1 = 4;
s1.int1 = 5;
deccvdbl(6.0,&s1.dec1);
s1.char1 = '7';
(void) strcpy(s1.string1, "eight");
(void) strcpy(s1.carray1, "nine");
if (Fvstot((char *)&s1, data, "test") == -1) {
printf("Fvstot failed: %s&bsoln", Fstrerror(Ferror));
exit(0);
}
/* transfer to target machine and get response */
...
/* translate back */
if (Fvttos(data, (char *)&s1, "test") == -1) {
printf("Fvttos failed: %s&bsoln", Fstrerror(Ferror));
exit(0);
}
/* use the structure */
.....
exit(0);
}
Fintro(3fml),
Fvftos(3fml),
Fvstof(3fml),
decimal(3c),
viewfile(5),