diff options
Diffstat (limited to 'pkg/tbtables/tbzlin.x')
| -rw-r--r-- | pkg/tbtables/tbzlin.x | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/pkg/tbtables/tbzlin.x b/pkg/tbtables/tbzlin.x new file mode 100644 index 00000000..7ab68e94 --- /dev/null +++ b/pkg/tbtables/tbzlin.x @@ -0,0 +1,190 @@ +include <chars.h> +include <ctype.h> +include "tbltext.h" + +# tbzlin -- get next line from text file +# This routine calls getlline (get long line) to get a line from a text file. +# The line_type indicates what type of line (comment, data, etc) was read. +# If the input line is data rather than a comment, the returned line will +# be terminated by EOS rather than by '\n'. If the line is a comment, the +# entire line (including newline) is returned. In the case of in-line +# comments, if there are non-whitespace characters preceding the '#' they +# will be returned, and the '#' will be replaced by EOS. A '#' which is +# enclosed in quotes (single or double) or preceded by '\' will not be +# counted as a comment character. A newline terminates the string regardless +# of what precedes or follows it; a newline within a string is an error, +# though. The function value is the number of characters preceding the EOS, +# or EOF is returned when the end of file is reached. +# +# The buffer is scanned to be sure it contains a '\n'. If not, we haven't +# read the entire line (i.e. it's longer than maxch); we regard that as +# a serious error. +# +# Phil Hodge, 6-Feb-1992 Function created. +# Phil Hodge, 19-Jan-1995 Allow continuation lines. +# Phil Hodge, 26-Dec-1995 Errchk getlline. +# Phil Hodge, 21-Apr-1999 Change error message if newline not found; +# allow last line of file to not have a newline. +# Phil Hodge, 7-Jun-1999 Change last argument from comment flag (bool) +# to line type (int); add line, and increment. + +int procedure tbzlin (fd, buf, maxch, line, line_type) + +int fd # i: fd for the file +char buf[ARB] # o: buffer for the line that was read +int maxch # i: size of line buffer +int line # io: incremented each time a line is read from file +int line_type # o: type of line returned in buf +#-- +pointer sp +pointer scratch +char ch # a character from the string which was read +int ip # counter for a character in the string +int nchar # number of char read by getlline +bool done # loop-termination flag +bool at_end # true when we reach the end of the line ('\n') +bool odd_squotes # true if current character is within quoted string +bool odd_dquotes # true if current char is within double quoted string +int getlline(), strlen(), strncmp() +errchk getlline + +begin + line_type = COMMENT_LINE # default + + nchar = getlline (fd, buf, maxch) + if (nchar == EOF) + return (EOF) # end of file reached + line = line + 1 + + # Check for special cases. + + done = false + if (strncmp (buf, "#k ", 3) == 0 || + strncmp (buf, "#K ", 3) == 0) { + line_type = KEYWORD_LINE + done = true + } else if ((strncmp (buf, "#c ", 3) == 0 || + strncmp (buf, "#C ", 3) == 0) && nchar > 4) { + # the test on nchar is because a column name must be specified + line_type = COLDEF_LINE + done = true + } + if (done) { + if (buf[nchar] == NEWLINE) { + buf[nchar] = EOS + nchar = nchar - 1 + } + return (nchar) + } + + # Blank up through maxch? Treat it as a comment. + ip = 1 + while (IS_WHITE(buf[ip]) && ip < maxch) # skip whitespace + ip = ip + 1 + if (ip >= maxch) + line_type = COMMENT_LINE + else if (buf[ip] == NEWLINE || buf[ip] == '#' || buf[ip] == EOS) + line_type = COMMENT_LINE + else + line_type = DATA_LINE + + # If there's no newline, and if this is not the last line of the + # file, we haven't read the entire line (i.e. it's longer than the + # buffer size). + # Also check whether the newline has been escaped, in which case + # we need to read further lines and concatenate them. + done = false + while (!done) { + ip = strlen (buf) + if (buf[ip] != NEWLINE) { + # The last line of the file need not have a newline. + call smark (sp) + call salloc (scratch, 2*SZ_LINE, TY_CHAR) + nchar = getlline (fd, Memc[scratch], 2*SZ_LINE) + if (nchar != EOF) { + call error (1, + "Unknown table type, or line too long for text file.") + } + call sfree (sp) + break + } + done = true # may be reset below + if (ip > 1) { + if (buf[ip-1] == ESCAPE) { # newline is escaped + done = false + # Read another line, clobbering the '\' and newline. + ip = ip - 1 # now points to the '\' + nchar = getlline (fd, buf[ip], maxch-ip) + line = line + 1 + + if (line_type == COMMENT_LINE) { + # Remove comment character from continuation line. + while (IS_WHITE(buf[ip]) && ip < maxch) + ip = ip + 1 + if (buf[ip] == '#') + buf[ip] = ' ' + } + } + } + } + + if (line_type != COMMENT_LINE) { + + # The current line is not a comment or blank; + # replace '\n' or '#' by EOS. + + # Skip leading whitespace and check whether the first character + # begins a quoted string. + ip = 1 + while (IS_WHITE(buf[ip]) && ip < maxch) + ip = ip + 1 + if (buf[ip] == SQUOTE) + odd_squotes = true + else + odd_squotes = false + if (buf[ip] == DQUOTE) + odd_dquotes = true + else + odd_dquotes = false + + ip = ip + 1 + at_end = false + while ( !at_end ) { + ch = buf[ip] + # Check for end of buffer or newline or in-line comment. + if (ch == NEWLINE) { + buf[ip] = EOS + at_end = true + } else if (ch == SQUOTE) { + # Toggle flag for in/out of quoted string. + odd_squotes = !odd_squotes + ip = ip + 1 + } else if (ch == DQUOTE) { + odd_dquotes = !odd_dquotes + ip = ip + 1 + } else if (ch == '#') { + # '#' is not a comment if it's in a quoted string + if (odd_squotes || odd_dquotes) { + ip = ip + 1 + # ... or if it's escaped. + } else if (buf[ip-1] == ESCAPE) { + ip = ip + 1 + } else { # it's an in-line comment + buf[ip] = EOS + at_end = true + } + } else if (ch == EOS) { + at_end = true + } else if (ip >= maxch) { # end of buffer reached + at_end = true # (can't get here) + buf[maxch+1] = EOS + } else { + ip = ip + 1 + } + } + if (odd_squotes || odd_dquotes) + call error (1, "tbzlin: newline within string") + nchar = ip - 1 + } + return (nchar) +end |