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Text File | 1987-11-18 | 14.4 KB | 191 lines

@@creat - create unbuffered io file. $$ █▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀█ █ THIS IS A SAMPLE OF THE SOFTEK C LANGUAGE REFERENCE FILE █ █ The complete C Language On-Line Reference files will soon █ █ be available for purchase from SofTek for only $9.95 █ █▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄█ ╔═════════════════════════════════════════════════════════════════════════════╗ ║ NAME: creat ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ DESCRIPTION: create a file and open for unbuffered i/o. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ USAGE: creat(name,pmode) ║ ║ char *name; ║ ║ int pmode; ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ NOTES: creat() creates a file and opens it for unbuffered, write-only ║ ║ access. If the file already exists, it is truncated so that ║ ║ nothing is in it. creat() returns as its value an integer called ║ ║ a 'file descriptor'. Whenever a call is made to one of the ║ ║ unbuffered i/o functions to access the file, its file descriptor ║ ║ must be included in the functions parameters. ║ ║ NAME is a pointer to a character string which is the name of the ║ ║ device or file to be opened. ║ ║ PMODE is optional. If specified, it is ignored. It should be ║ ║ included, however, for programs for which UNIX compatibility ║ ║ is required, since the UNIX creat() function requires it. In ║ ║ this case, PMODE should have the octal value 0666. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ ERROR INFO: If creat() fails, it returns -1 as its value and sets a code ║ ║ in the global integer ERRNO. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ LIBRARY: x.lib ║ ║ ║ ╚═════════════════════════════════════════════════════════════════════════════╝ @@exp - compute exponential. $$ █▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀█ █ THIS IS A SAMPLE OF THE SOFTEK C LANGUAGE REFERENCE FILE █ █ The complete C Language On-Line Reference files will soon █ █ be available for purchase from SofTek for only $9.95 █ █▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄█ ╔═════════════════════════════════════════════════════════════════════════════╗ ║ NAME: exp ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ DESCRIPTION: compute exponential. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ USAGE: double exp(x) ║ ║ double x; ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ NOTES: none. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ ERROR INFO: If unsuccessful, the function sets an error code in the global ║ ║ integer ERRNO and returns an arbitrary value; otherwise ║ ║ it returns the computed value without modifying ERRNO. The ║ ║ symbolic values which the function can place in ERRNO are ║ ║ EDOM, signifying that the argument was invalid, and ERANGE, ║ ║ meaning that the value of the function couldn't be computed. ║ ║ The codes are defined in the file 'errno.h'. ║ ║ The following table lists the errorcodes that can be returned, ║ ║ the function value for that error, and the meaning of the ║ ║ error. The symbolic values are defined in the file 'math.h'. ║ ║ ║ ║ ****************************************************************║ ║ * function | error | f(x) | meaning *║ ║ *============|============|=============|======================*║ ║ * exp | ERANGE | HUGE | x > LOGHUGE *║ ║ * exp | ERANGE | 0.0 | x < LOGTINY *║ ║ ****************************************************************║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ LIBRARY: x.lib ║ ║ ║ ╚═════════════════════════════════════════════════════════════════════════════╝ @@fopen - open buffered io stream. $$ █▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀█ █ THIS IS A SAMPLE OF THE SOFTEK C LANGUAGE REFERENCE FILE █ █ The complete C Language On-Line Reference files will soon █ █ be available for purchase from SofTek for only $9.95 █ █▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄█ ╔═════════════════════════════════════════════════════════════════════════════╗ ║ NAME: fopen ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ DESCRIPTION: open i/o stream. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ USAGE: FILE *fopen(filename, mode) ║ ║ char *filename, *mode; ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ NOTES: fopen() opens the device or file specified by the FILENAME parameter ║ ║ for access by the standard i/o functions specified by the MODE ║ ║ parameter. The open file or device is called a 'stream'. ║ ║ If the file or device is successfully opened, the function returns ║ ║ a file pointer to a structure of type file. This file pointer ║ ║ will be used for future accesses to the open stream. ║ ║ MODE points to a character string which specifies how the user's ║ ║ program intends to access the stream. The choices are as follows: ║ ║ r - Open for reading only. If a file is opened, it is positioned ║ ║ at the first character in it. If the file or device does not ║ ║ exist, NULL is returned. ║ ║ w - Open for writing only. If a file is opened which already ║ ║ exist, it is truncated to zero length. If the file does ║ ║ not exist, it is created. ║ ║ a - Open for appending. The calling program is granted write only ║ ║ access to the stream. The current file position is the ║ ║ character after the last character in the file. If the file ║ ║ does not exist, it is created. ║ ║ x - Open for writing. The file must NOT previously exist. This ║ ║ option is NOT supported by UNIX. ║ ║ r+ - Open for reading and writing. Same as 'r', but the stream ║ ║ may also be written to. ║ ║ w+ - Open for writing and reading. Same as 'w', but the stream ║ ║ may also be read; different from 'r+' in the creation of a ║ ║ new file and loss of any previous one. ║ ║ a+ - Open for appending and reading. Same as 'a' but the stream ║ ║ may also be read; different from 'r+' in file positioning ║ ║ and file creation. ║ ║ x+ - Open for writing and reading. Same as 'x' but the file can ║ ║ also be read. ║ ║ On systems which don't keep track of the last character in a file ║ ║ (such as CP/M and Apple DOS), not all files can be correctly ║ ║ positioned when opened in append mode. ║ ║ FILENAME is a pointer to a character string which is the name ║ ║ of the device or file to be opened. ║ ║ The header 'stdio.h' must be included before this function can ║ ║ be used. ║ ║ EXAMPLE: ║ ║ if ((fp = fopen(*fname, *fmode)) == NULL) ║ ║ printf("unable to open specified file"); ║ ║ else ║ ║ printf("file is open"); ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ ERROR INFO: If the file or device cannot be opened, NULL is returned and ║ ║ an error code is set in the global integer ERRNO. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ LIBRARY: x.lib ║ ║ ║ ╚═════════════════════════════════════════════════════════════════════════════╝ @@fread - read binary data from a buffered io stream. $$ █▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀█ █ THIS IS A SAMPLE OF THE SOFTEK C LANGUAGE REFERENCE FILE █ █ The complete C Language On-Line Reference files will soon █ █ be available for purchase from SofTek for only $9.95 █ █▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄█ ╔═════════════════════════════════════════════════════════════════════════════╗ ║ NAME: fread ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ DESCRIPTION: read binary data from an i/o stream. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ USAGE: int fread(buffer, size, count, stream) ║ ║ char *buffer; ║ ║ int size, count; ║ ║ FILE *stream; ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ NOTES: fread() performs a buffered input operation to the open stream ║ ║ specified by the parameter STREAM. ║ ║ BUFFER is the address of the user's buffer which will be used ║ ║ for the operation. ║ ║ The function reads COUNT items, each containing SIZE bytes, from ║ ║ the stream. ║ ║ The function performs i/o using the function getc(), thus no ║ ║ translations occur on the data being transferred. ║ ║ The function returns as its value the number of items actually ║ ║ read. ║ ║ The header 'stdio.h' must be included before use of this function. ║ ║ EXAMPLE ║ ║ This is the code for reading ten integers from file 1 and writing ║ ║ then again to file 2. It includes a simple check that there are ║ ║ enough two-byte items in the first file: ║ ║ #include "stdio.h" ║ ║ main() ║ ║ { ║ ║ FILE *fp1, *fp2, *fopen(); ║ ║ char *buf; ║ ║ int size = 2, count = 10; ║ ║ ║ ║ fp1 = fopen("file1","r"); ║ ║ fp2 = fopen("file2","w"); ║ ║ if (fread(buf, size, count, fp1) != count) ║ ║ printf("Not enough integers in file 1\n"); ║ ║ fwrite(buf, size, count, fp2); ║ ║ } ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ ERROR INFO: fread() returns 0 upon end of file or error. The functions ║ ║ feof() and ferror() can be used to distinguish between ║ ║ the two. In case of error, the global integer ERRNO ║ ║ contains a code defining the error. ║ ╟─────────────────────────────────────────────────────────────────────────────╢ ║ LIBRARY: x.lib ║ ╚═════════════════════════════════════════════════════════════════════════════╝