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# 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
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