diff options
Diffstat (limited to 'iop.c')
| -rw-r--r-- | iop.c | 237 |
1 files changed, 237 insertions, 0 deletions
@@ -0,0 +1,237 @@ +/* + * iop.c - do i/o related things. + */ + +/* + * Copyright (C) 1986, 1988, 1989, 1991 the Free Software Foundation, Inc. + * + * This file is part of GAWK, the GNU implementation of the + * AWK Progamming Language. + * + * GAWK is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 1, or (at your option) + * any later version. + * + * GAWK is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GAWK; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include "awk.h" + +#ifndef atarist +#define INVALID_HANDLE (-1) +#else +#include <stddef.h> +#include <fcntl.h> +#define INVALID_HANDLE (__SMALLEST_VALID_HANDLE - 1) +#endif /* atarist */ + + +#ifdef TEST +int bufsize = 8192; +#endif + +int +optimal_bufsize(fd) +int fd; +{ +#ifdef VMS +/* don't even bother trying [fstat() fails across DECnet] */ + return BUFSIZ; +#else + struct stat stb; + + /* + * System V doesn't have the file system block size in the + * stat structure. So we have to make some sort of reasonable + * guess. We use stdio's BUFSIZ, since that is what it was + * meant for in the first place. + */ +#ifdef BLKSIZE_MISSING +#define DEFBLKSIZE BUFSIZ +#else +#define DEFBLKSIZE (stb.st_blksize ? stb.st_blksize : BUFSIZ) +#endif + +#ifdef TEST + return bufsize; +#endif +#ifndef atarist + if (isatty(fd)) +#else + /* + * On ST redirected stdin does not have a name attached + * (this could be hard to do to) and fstat would fail + */ + if (0 == fd || isatty(fd)) +#endif /*atarist */ + return BUFSIZ; + if (fstat(fd, &stb) == -1) + fatal("can't stat fd %d (%s)", fd, strerror(errno)); + if (lseek(fd, 0L, 0) == -1) + return DEFBLKSIZE; + return (stb.st_size < DEFBLKSIZE ? stb.st_size : DEFBLKSIZE); +#endif /*! VMS */ +} + +IOBUF * +iop_alloc(fd) +int fd; +{ + IOBUF *iop; + + if (fd == INVALID_HANDLE) + return NULL; + emalloc(iop, IOBUF *, sizeof(IOBUF), "iop_alloc"); + iop->flag = 0; + if (isatty(fd)) + iop->flag |= IOP_IS_TTY; + iop->size = optimal_bufsize(fd); + errno = 0; + iop->fd = fd; + emalloc(iop->buf, char *, iop->size + 2, "iop_alloc"); + iop->end = iop->off = iop->buf; + iop->secsiz = iop->size < BUFSIZ ? iop->size : BUFSIZ; + emalloc(iop->secbuf, char *, iop->secsiz+2, "iop_alloc"); + iop->cnt = -1; + return iop; +} + +int +get_a_record(out, iop, rs) +char **out; +IOBUF *iop; +register int rs; +{ + register char *bp = iop->off; + register char *end_data = iop->end; /* end of current data read */ + char *end_buf = iop->buf + iop->size; /* end of input buffer */ + char *start = iop->off; /* beginning of record */ + char *offset = iop->secbuf; /* end of data in secbuf */ + size_t size; + + if (iop->cnt == 0) + return EOF; + + /* set up sentinels */ + if (rs == 0) { + *end_data = *(end_data+1) = '\n'; + *end_buf = *(end_buf+1) = '\n'; + } else + *end_data = *end_buf = rs; + + for (;;) { /* break on end of record, read error or EOF */ + + if (bp == end_data) { + if (bp == end_buf) { /* record spans buffer end */ +#ifdef atarist +#define P_DIFF ptrdiff_t +#else +#define P_DIFF int +#endif +#define COPY_TO_SECBUF { \ + P_DIFF oldlen = offset - iop->secbuf; \ + P_DIFF newlen = bp - start; \ + \ + if (iop->secsiz < oldlen + newlen) { \ + erealloc(iop->secbuf, char *, \ + oldlen+newlen, "get_record"); \ + offset = iop->secbuf + oldlen; \ + } \ + memcpy(offset, start, newlen); \ + offset += newlen; \ + } + COPY_TO_SECBUF + start = bp = iop->buf; + size = iop->size; + } else + size = end_buf - bp; + iop->cnt = read(iop->fd, bp, size); + if (iop->cnt == -1) + fatal("error reading input"); + else if (iop->cnt == 0) { + break; + } else { + end_data = bp + iop->cnt; + if (rs == 0 && *bp == '\n' + && offset > iop->secbuf + && *(offset-1) == '\n') { + bp++; + break; + } + if (rs == 0) { + *end_data = *(end_data+1) = '\n'; + *end_buf = *(end_buf+1) = '\n'; + } else + *end_data = rs; + } + } + if (rs == 0) { + for (;;) { + if (*bp++ == '\n' && *bp == '\n') { + bp++; + break; + } + } + } else + while (*bp++ != rs) + ; + if (bp <= end_data) /* end of record */ + break; + bp = end_data; + } + if (offset == iop->secbuf && start == bp && iop->cnt == 0) { + *out = start; + return EOF; + } + iop->off = bp; + iop->end = end_data; + if (offset != iop->secbuf) { + if (start != bp) + COPY_TO_SECBUF + start = iop->secbuf; + bp = offset; + } + if (rs == 0) { + if (*--bp == '\n') { + *bp = '\0'; + if (*--bp == '\n') + *bp = '\0'; + else + bp++; + } else + bp++; + } else if (*--bp == rs) + ; + else + bp++; + *bp = '\0'; + *out = start; + return bp - start; +} + +#ifdef TEST +main(argc, argv) +int argc; +char *argv[]; +{ + IOBUF *iop; + char *out; + int cnt; + + if (argc > 1) + bufsize = atoi(argv[1]); + iop = iop_alloc(0); + while ((cnt = get_a_record(&out, iop, 0)) > 0) { + fwrite(out, 1, cnt, stdout); + fwrite("\n", 1, 1, stdout); + } +} +#endif |