Return to copen.c CVS log

Up to [CSRG BSD Unix] / 43BSDTahoe / new / cpm / src

Annotation of 43BSDTahoe/new/cpm/src/copen.c, revision 1.1

1.1     ! root        1: /*     copen.c 1.8     85/03/24        */
        !             2: 
        !             3: #include <stdio.h>
        !             4: #include "cpmio.h"
        !             5: #include "cpmfio.h"
        !             6: 
        !             7: /*
        !             8:  * Open cp/m file with the given file name and extension, return
        !             9:  * file pointer. A null pointer is returned if the file could not
        !            10:  * be opened. mode tells whether the file is to be read, written
        !            11:  * or both.
        !            12:  */
        !            13: 
        !            14: C_FILE *
        !            15: c_open(name, ext, mode)
        !            16:        char *name, *ext;
        !            17: {
        !            18: 
        !            19:        register int    i, index, scnt;
        !            20:        register C_FILE *fptr;
        !            21:        char *malloc(), *fixname();
        !            22: 
        !            23:        if ((index = searchdir(name, ext)) == -1) {
        !            24:                fprintf(stderr, "file not found: %s\n", fixname(name, ext));
        !            25:                return (NULL);
        !            26:        }
        !            27:        /* test for legal mode */
        !            28:        if (!(mode & RW)) {
        !            29:                fprintf(stderr, "open: illegal mode - %d\n", mode);
        !            30:                return (NULL);
        !            31:        }
        !            32: #ifdef DEBUG
        !            33:        printf("directory index: %d\n", index); 
        !            34: #endif
        !            35:        for ((i = 0, fptr=c_iob); i < C_NFILE; i++,fptr++)
        !            36:                if (!(fptr->c_flag)) 
        !            37:                        break;
        !            38:        if (i == C_NFILE) {
        !            39:                fprintf(stderr, "too many open files\n");
        !            40:                return (NULL);
        !            41:        }
        !            42: 
        !            43: /*
        !            44:  * Free file descriptor slot found, initialize field, allocate
        !            45:  * memory and read first block.
        !            46:  */
        !            47:        if ((fptr->c_buf = malloc(blksiz)) == NULL) {
        !            48:                printf("c_open: no memory!\n");
        !            49:                return (NULL);
        !            50:        }
        !            51:        fptr->c_extno = 0;
        !            52:        fptr->c_base = fptr->c_buf;
        !            53:        fptr->c_flag = mode;
        !            54:        fptr->c_blk = 0;
        !            55:        fptr->c_ext = index;
        !            56:        fptr->c_dirp = dirbuf+index;
        !            57:        fptr->c_seccnt = 0xff &(dirbuf+index)->blkcnt;
        !            58:        scnt = (fptr->c_seccnt > blksiz/seclth) ? blksiz/seclth:fptr->c_seccnt;
        !            59: #ifdef DEBUG
        !            60:        printf("c_open: scnt=%d\n",scnt); 
        !            61: #endif
        !            62:        if (getblock(0xff &(int)fptr->c_dirp->pointers[0], fptr->c_buf, scnt)
        !            63:                                                                == EOF)
        !            64:                return (NULL);
        !            65:        fptr->c_cnt = seclth*scnt;
        !            66:        fptr->c_seccnt -= scnt;
        !            67:        return (fptr);
        !            68: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.