diff options
Diffstat (limited to 'sys/etc/prgline.x')
| -rw-r--r-- | sys/etc/prgline.x | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/sys/etc/prgline.x b/sys/etc/prgline.x new file mode 100644 index 00000000..21ec1780 --- /dev/null +++ b/sys/etc/prgline.x @@ -0,0 +1,204 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <config.h> +include <syserr.h> +include <ctype.h> +include <fset.h> + +define XMIT 0 +define XFER 1 + +# PRGETLINE -- Get a line of text from a process. The function is equivalent +# to the ordinary FIO getline with the exception that pseudofile read and +# write directives are intercepted and processed. Hence, the reader sees a +# stream of application specific commands need not know about pseudofile i/o. +# The function of PRGETLINE is such that it can be used in place of GETLINE +# on any file; pseudofile directives are recognized and process only if the +# FD is associated with a connected subprocess. + +int procedure prgetline (fd, lbuf) + +int fd # parent's input IPC from child process +char lbuf[SZ_LINE] # output line buffer + +char ch +int nchars, maxchars, nchars_read, raw_mode_set, ndigits +int bufsize, outfd, destfd, pr, pseudofile, line_type, offset +pointer sp, buf, ip + +char getc() +int getline(), read(), fstati(), ctoi(), itoc() +errchk syserr, getline, fstati, read, write, pr_decodeargs, putc, getc +include "prc.com" + +begin + call smark (sp) + + pr = 0 + buf = NULL + raw_mode_set = 0 + + repeat { + nchars = getline (fd, lbuf) + + # Return immediately if not XMIT or XFER directive. This code is + # exercised heavily when performing raw mode i/o, hence some + # clarity is sacrificed for the sake of efficiency. + # + # Syntax: "xmit(P,NNN)" or "xfer(P,NNN)" + # 12345678 12345678 + # + # where P is the pseudofile code (0<P<10) and NNN is the size of + # the data block in chars. In the following code all explicit + # integer constants refer to the character offsets shown above. + + if (lbuf[1] != 'x' || nchars == EOF) { + break + } else if (lbuf[2] == 'm') { + if (lbuf[3] == 'i' && lbuf[4] == 't' && lbuf[5] == '(') { + line_type = XMIT + pseudofile = TO_INTEG (lbuf[6]) + } else + break + } else if (lbuf[2] == 'f') { + if (lbuf[3] == 'e' && lbuf[4] == 'r' && lbuf[5] == '(') { + line_type = XFER + pseudofile = TO_INTEG (lbuf[6]) + } else + break + } else + break + + # Ignore directive if FD not associated with a process. To minimize + # searches of the process table we keep track of the slot number + # of the last active pid. + + if (pr == 0) { + if (pr_infd[pr_lastio] == fd && pr_pid[pr_lastio] != NULL) + pr = pr_lastio + else { + for (pr=1; pr <= MAX_CHILDPROCS; pr=pr+1) + if (pr_pid[pr] != NULL) + if (pr_infd[pr] == fd) + break + if (pr > MAX_CHILDPROCS) + break + pr_lastio = pr + } + outfd = pr_outfd[pr] + } + + # Map pseudofile code to a file descriptor in the local process. + + destfd = pr_pstofd[pr,pseudofile] + + + # RAW mode transfers are handled as a special case to minimize the + # per-character overhead. + + if (lbuf[8] == '1' && lbuf[9] == ')') { + if (line_type == XMIT) { + # XMIT + if (getc (fd, ch) == EOF) + call syserr (SYS_PRIPCSYNTAX) + + # Clear RAW input mode if newline is encountered in output. + # Only works for STDIN/STDOUT, but that is all raw mode is + # used for with pseudofiles. + + if (ch == '\n') + if (destfd == STDOUT) { + call fseti (STDIN, F_RAW, NO) + if (raw_mode_set == STDIN) + raw_mode_set = 0 + } + + call putc (destfd, ch) + call flush (destfd) + + } else { + # XFER + if (raw_mode_set != destfd) { + call fseti (destfd, F_RAW, YES) + raw_mode_set = destfd + } + + if (getc (destfd, ch) == EOF) + call putline (outfd, "0\n") + else { + call putline (outfd, "1\n") + call flush (outfd) + call putc (outfd, ch) + } + call flush (outfd) + } + next + } + + + # GENERAL XMIT or XFER directive. Read a block of data from one + # stream and transmit it to the other stream. + + if (buf == NULL) { + bufsize = fstati (fd, F_BUFSIZE) + call salloc (buf, bufsize, TY_CHAR) + } + + offset = 8 + if (ctoi (lbuf, offset, nchars) <= 0) + call syserr (SYS_PRIPCSYNTAX) + + if (line_type == XMIT) { + # XMIT -- Copy the block of data from the IPC channel to the + # destination file. + + nchars_read = read (fd, Memc[buf], nchars) + if (nchars_read != nchars) + call syserr (SYS_PRIPCSYNTAX) + else { + # Clear RAW input mode if set and newline is encountered + # in the output stream. + + if (destfd == STDOUT) + if (fstati (STDIN, F_RAW) == YES) + for (ip=buf+nchars-1; ip >= buf; ip=ip-1) + if (Memc[ip] == '\n') { + call fseti (STDIN, F_RAW, NO) + if (raw_mode_set == STDIN) + raw_mode_set = 0 + break + } + + call write (destfd, Memc[buf], nchars) + call flush (destfd) + } + next + + } else { + # XFER -- Read up to maxchars chars from the input file and + # pass them on to the output IPC channel. + + maxchars = min (nchars, bufsize) + nchars = read (destfd, Memc[buf], maxchars) + if (nchars == EOF) + nchars = 0 + + # Write the byte count record followed by the data record. + # These must be written as two separate records or deadlock + # will occur (with the reader waiting for the second record). + + ndigits = itoc (nchars, lbuf, SZ_LINE) + lbuf[ndigits+1] = '\n' + call write (outfd, lbuf, ndigits + 1) + call flush (outfd) + + call write (outfd, Memc[buf], nchars) + call flush (outfd) + + next + } + } + + call sfree (sp) + return (nchars) +end |