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Diffstat (limited to 'pkg/system/help/hbgetblk.x')
| -rw-r--r-- | pkg/system/help/hbgetblk.x | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/pkg/system/help/hbgetblk.x b/pkg/system/help/hbgetblk.x new file mode 100644 index 00000000..a39db034 --- /dev/null +++ b/pkg/system/help/hbgetblk.x @@ -0,0 +1,195 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <ctype.h> +include "help.h" + +.help hb_getnextblk +.nf ___________________________________________________________________________ +HB_GETNEXTBLK -- Scan a file for the next help block, i.e., block of lines +delimited by ".help" and ".endhelp". The syntax of a help block header is +as follows: + + .help[typestr] key1,key2,...,keyN section title + +Whitespace is NOT permitted in the keyword list unless it is quoted. Quotes +are optional for each of the three strings. If the line ends with the +backslash character or a comma we assume that the header is continued on the +next line. The typestr, denoting the type of help block, is optional. +If absent it defaults to "hlp". System help blocks are of type "sys". + +We keep track of the file line number when searching for a help block. The +line number is updated in the HB structure. For this number to be accurate, +the caller must see that it is initialized before we are called. +.endhelp ______________________________________________________________________ + +define SZ_SBUF (MAX_KEYS * SZ_KEY) +define IS_KEYWCHAR (IS_ALNUM($1) || $1 == '_' || $1 == '$') +define exit_ 90 + + +int procedure hb_getnextblk (hb, ctrl) + +pointer hb +pointer ctrl + +bool at_eof +char key[SZ_KEY] +int fd, n, ip, op, junk +pointer sp, lbuf, sbuf, p +int hb_getstr(), strmatch(), getline(), strlen() + +begin + call smark (sp) + call salloc (lbuf, SZ_LINE, TY_CHAR) + call salloc (sbuf, SZ_SBUF, TY_CHAR) + + # Search forward for the next help block. + fd = H_IN(ctrl) + at_eof = true + + while (getline (fd, Memc[lbuf]) != EOF) { + HB_LINENO(hb) = HB_LINENO(hb) + 1 + if (strmatch (Memc[lbuf], "^.{help}") > 0) { + at_eof = false + break + } + } + + if (at_eof) { + call sfree (sp) + return (EOF) + } + + # Initialize everything in case of an early exit. + HB_TYPE(hb) = TY_UNKNOWN + HB_NKEYS(hb) = 0 + HB_TYPESTR(hb) = EOS + HB_SECTION(hb) = EOS + HB_TITLE(hb) = EOS + + # Decode help block into the HB structure. First step is to + # get the type suffix string, if any. + + ip = strlen (".help") + 1 + p = lbuf + ip - 1 + if (IS_ALPHA (Memc[p])) { + for (n=0; IS_ALNUM (Memc[p+n]); n=n+1) + ; + call strcpy (Memc[p], HB_TYPESTR(hb), min(n,SZ_TYPESTR)) + if ( strmatch (HB_TYPESTR(hb), "{sys}") > 0) + HB_TYPE(hb) = TY_SYS + else if (strmatch (HB_TYPESTR(hb), "{hlp}") > 0) + HB_TYPE(hb) = TY_HLP + else + HB_TYPE(hb) = TY_UNKNOWN + } else { + HB_TYPE(hb) = TY_HLP + n = 0 + } + ip = ip + n + + # Now get the keyword string, and break the keywords out into + # the keyword list. + + if (hb_getstr (fd, Memc[lbuf], ip, Memc[sbuf], SZ_SBUF, + HB_LINENO(hb)) == 0) + goto exit_ + + p = sbuf + while (IS_WHITE (Memc[p]) || Memc[p] == ',') + p = p + 1 + for (n=1; n <= MAX_KEYS && Memc[p] != EOS; n=n+1) { + for (op=1; IS_KEYWCHAR (Memc[p]); op=op+1) { + key[op] = Memc[p] + p = p + 1 + } + key[op] = EOS + call strcpy (key, HB_KEY(hb,n), SZ_KEY) + while (IS_WHITE (Memc[p]) || Memc[p] == ',') + p = p + 1 + } + HB_NKEYS(hb) = n - 1 + + # Fetch section label string and title string. + + if (hb_getstr (fd, Memc[lbuf], ip, HB_SECTION(hb), SZ_SECTION, + HB_LINENO(hb)) == 0) + goto exit_ + junk = hb_getstr (fd, Memc[lbuf], ip, HB_TITLE(hb), SZ_TITLE, + HB_LINENO(hb)) + +exit_ call sfree (sp) + return (HB_LINENO(hb)) +end + + +# HB_GETSTR -- Fetch a string (optionally quoted) from the line buffer. +# Handle everything having to do with continuation. + +int procedure hb_getstr (fd, lbuf, ip, outstr, maxch, lineno) + +int fd +char lbuf[ARB] +int ip +char outstr[ARB] +int maxch +int lineno + +char ch +int op, dstart +int stridx(), getline() +string delim " \t'\"" + +begin + while (IS_WHITE (lbuf[ip])) + ip = ip + 1 + op = 1 + + # If quoted string, only a quote can end the string. + dstart = 1 + if (lbuf[ip] == '\'' || lbuf[ip] == '"') { + ip = ip + 1 + dstart = 3 + } + + # Fetch the string. + for (ch=lbuf[ip]; stridx (ch, delim[dstart]) == 0; ch=lbuf[ip]) { + if (op >= maxch) + break + + switch (ch) { + case '\\', ',': + if (lbuf[ip+1] == '\n' || lbuf[ip+1] == EOS) { + # Continue on next line. + if (getline (fd, lbuf) == EOF) + lbuf[1] = EOS + else + lineno = lineno + 1 + ip = 1 + if (ch == '\\') + next + } else + ip = ip + 1 + outstr[op] = ch + op = op + 1 + + case '\n', EOS: + if (delim[dstart] == '\'') { + call eprintf ("Missing right quote in helpfile, line %d\n") + call pargi (lineno) + } + break + + default: + outstr[op] = ch + op = op + 1 + ip = ip + 1 + } + } + + if (ch != EOS) + ip = ip + 1 + outstr[op] = EOS + + return (op - 1) +end |