implement -h (synopsis only) for preformatted (cat) pages;

[mandoc.git] / main.c

diff --git a/main.c b/main.c
index 8a4e9fa93363c17f83da0656da5655af86c34869..e56b2dbc3a898bed41d5c7596002479b5d13b31a 100644 (file)
--- a/main.c
+++ b/main.c
@@ -1,6 +1,6 @@
-/*     $Id: main.c,v 1.181 2014/08/20 21:04:35 schwarze Exp $ */
+/*     $Id: main.c,v 1.197 2014/11/11 02:10:04 schwarze Exp $ */

 /*
 /*

- * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+ * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>

  * Copyright (c) 2010, 2011, 2012, 2014 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2010 Joerg Sonnenberger <joerg@netbsd.org>
  *
  * Copyright (c) 2010, 2011, 2012, 2014 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2010 Joerg Sonnenberger <joerg@netbsd.org>
  *


@@ -21,6 +21,9 @@
 #include <sys/types.h>
 
 #include <assert.h>
 #include <sys/types.h>
 
 #include <assert.h>

+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>

 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>


@@ -61,7 +64,6 @@ enum  outt {
        OUTT_TREE,      /* -Ttree */
        OUTT_MAN,       /* -Tman */
        OUTT_HTML,      /* -Thtml */
        OUTT_TREE,      /* -Ttree */
        OUTT_MAN,       /* -Tman */
        OUTT_HTML,      /* -Thtml */

-       OUTT_XHTML,     /* -Txhtml */

        OUTT_LINT,      /* -Tlint */
        OUTT_PS,        /* -Tps */
        OUTT_PDF        /* -Tpdf */
        OUTT_LINT,      /* -Tlint */
        OUTT_PS,        /* -Tps */
        OUTT_PDF        /* -Tpdf */


@@ -69,6 +71,7 @@ enum  outt {
 
 struct curparse {
        struct mparse    *mp;
 
 struct curparse {
        struct mparse    *mp;

+       struct mchars    *mchars;       /* character table */

        enum mandoclevel  wlevel;       /* ignore messages below this */
        int               wstop;        /* stop after a file with a warning */
        enum outt         outtype;      /* which output to use */
        enum mandoclevel  wlevel;       /* ignore messages below this */
        int               wstop;        /* stop after a file with a warning */
        enum outt         outtype;      /* which output to use */


@@ -79,16 +82,20 @@ struct      curparse {
        char              outopts[BUFSIZ]; /* buf of output opts */
 };
 
        char              outopts[BUFSIZ]; /* buf of output opts */
 };
 

+static int               koptions(int *, char *);

 static int               moptions(int *, char *);
 static void              mmsg(enum mandocerr, enum mandoclevel,
                                const char *, int, int, const char *);
 static void              parse(struct curparse *, int,
                                const char *, enum mandoclevel *);
 static int               moptions(int *, char *);
 static void              mmsg(enum mandocerr, enum mandoclevel,
                                const char *, int, int, const char *);
 static void              parse(struct curparse *, int,
                                const char *, enum mandoclevel *);

+static enum mandoclevel  passthrough(const char *, int, int);
+static void              spawn_pager(void);

 static int               toptions(struct curparse *, char *);
 static void              usage(enum argmode) __attribute__((noreturn));
 static void              version(void) __attribute__((noreturn));
 static int               woptions(struct curparse *, char *);
 
 static int               toptions(struct curparse *, char *);
 static void              usage(enum argmode) __attribute__((noreturn));
 static void              version(void) __attribute__((noreturn));
 static int               woptions(struct curparse *, char *);
 

+static const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9};

 static const char       *progname;
 
 
 static const char       *progname;
 
 


@@ -101,12 +108,18 @@ main(int argc, char *argv[])
        char            *conf_file, *defpaths, *auxpaths;
        char            *defos;
 #if HAVE_SQLITE3
        char            *conf_file, *defpaths, *auxpaths;
        char            *defos;
 #if HAVE_SQLITE3

-       struct manpage  *res;
-       size_t           i, sz;
+       struct manpage  *res, *resp;
+       size_t           isec, i, sz;
+       int              prio, best_prio;
+       char             sec;

 #endif
        enum mandoclevel rc;
        enum outmode     outmode;
 #endif
        enum mandoclevel rc;
        enum outmode     outmode;

+       pid_t            child_pid;
+       int              fd;

        int              show_usage;
        int              show_usage;

+       int              use_pager;
+       int              synopsis_only;

        int              options;
        int              c;
 
        int              options;
        int              c;
 


@@ -138,12 +151,16 @@ main(int argc, char *argv[])
        memset(&curp, 0, sizeof(struct curparse));
        curp.outtype = OUTT_ASCII;
        curp.wlevel  = MANDOCLEVEL_FATAL;
        memset(&curp, 0, sizeof(struct curparse));
        curp.outtype = OUTT_ASCII;
        curp.wlevel  = MANDOCLEVEL_FATAL;

-       options = MPARSE_SO;
+       options = MPARSE_SO | MPARSE_UTF8 | MPARSE_LATIN1;

        defos = NULL;
 
        defos = NULL;
 

+       use_pager = 1;

        show_usage = 0;
        show_usage = 0;

+       synopsis_only = 0;

        outmode = OUTMODE_DEF;
        outmode = OUTMODE_DEF;

-       while (-1 != (c = getopt(argc, argv, "aC:fI:ikM:m:O:S:s:T:VW:w"))) {
+
+       while (-1 != (c = getopt(argc, argv,
+                       "aC:cfhI:iK:klM:m:O:S:s:T:VW:w"))) {

                switch (c) {
                case 'a':
                        outmode = OUTMODE_ALL;
                switch (c) {
                case 'a':
                        outmode = OUTMODE_ALL;


@@ -151,9 +168,17 @@ main(int argc, char *argv[])
                case 'C':
                        conf_file = optarg;
                        break;
                case 'C':
                        conf_file = optarg;
                        break;

+               case 'c':
+                       use_pager = 0;
+                       break;

                case 'f':
                        search.argmode = ARG_WORD;
                        break;
                case 'f':
                        search.argmode = ARG_WORD;
                        break;

+               case 'h':
+                       (void)strlcat(curp.outopts, "synopsis,", BUFSIZ);
+                       synopsis_only = 1;
+                       outmode = OUTMODE_ALL;
+                       break;

                case 'I':
                        if (strncmp(optarg, "os=", 3)) {
                                fprintf(stderr,
                case 'I':
                        if (strncmp(optarg, "os=", 3)) {
                                fprintf(stderr,


@@ -172,9 +197,17 @@ main(int argc, char *argv[])
                case 'i':
                        outmode = OUTMODE_INT;
                        break;
                case 'i':
                        outmode = OUTMODE_INT;
                        break;

+               case 'K':
+                       if ( ! koptions(&options, optarg))
+                               return((int)MANDOCLEVEL_BADARG);
+                       break;

                case 'k':
                        search.argmode = ARG_EXPR;
                        break;
                case 'k':
                        search.argmode = ARG_EXPR;
                        break;

+               case 'l':
+                       search.argmode = ARG_FILE;
+                       outmode = OUTMODE_ALL;
+                       break;

                case 'M':
                        defpaths = optarg;
                        break;
                case 'M':
                        defpaths = optarg;
                        break;


@@ -215,10 +248,13 @@ main(int argc, char *argv[])
        if (show_usage)
                usage(search.argmode);
 
        if (show_usage)
                usage(search.argmode);
 

+       /* Postprocess options. */
+

        if (outmode == OUTMODE_DEF) {
                switch (search.argmode) {
                case ARG_FILE:
                        outmode = OUTMODE_ALL;
        if (outmode == OUTMODE_DEF) {
                switch (search.argmode) {
                case ARG_FILE:
                        outmode = OUTMODE_ALL;

+                       use_pager = 0;

                        break;
                case ARG_NAME:
                        outmode = OUTMODE_ONE;
                        break;
                case ARG_NAME:
                        outmode = OUTMODE_ONE;


@@ -229,8 +265,26 @@ main(int argc, char *argv[])
                }
        }
 
                }
        }
 

+       /* Parse arguments. */
+

        argc -= optind;
        argv += optind;
        argc -= optind;
        argv += optind;

+#if HAVE_SQLITE3
+       resp = NULL;
+#endif
+
+       /* Quirk for a man(1) section argument without -s. */
+
+       if (search.argmode == ARG_NAME &&
+           argv[0] != NULL &&
+           isdigit((unsigned char)argv[0][0]) &&
+           (argv[0][1] == '\0' || !strcmp(argv[0], "3p"))) {
+               search.sec = argv[0];
+               argv++;
+               argc--;
+       }
+
+       rc = MANDOCLEVEL_OK;

 
        /* man(1), whatis(1), apropos(1) */
 
 
        /* man(1), whatis(1), apropos(1) */
 


@@ -238,22 +292,66 @@ main(int argc, char *argv[])
 #if HAVE_SQLITE3
                if (argc == 0)
                        usage(search.argmode);
 #if HAVE_SQLITE3
                if (argc == 0)
                        usage(search.argmode);

+
+               /* Access the mandoc database. */
+

                manpath_parse(&paths, conf_file, defpaths, auxpaths);
                mansearch_setup(1);
                if( ! mansearch(&search, &paths, argc, argv, &res, &sz))
                        usage(search.argmode);
                manpath_parse(&paths, conf_file, defpaths, auxpaths);
                mansearch_setup(1);
                if( ! mansearch(&search, &paths, argc, argv, &res, &sz))
                        usage(search.argmode);

-               manpath_free(&paths);
+               resp = res;
+
+               if (sz == 0) {
+                       if (search.argmode == ARG_NAME)
+                               fprintf(stderr, "%s: No entry for %s "
+                                   "in the manual.\n", progname, argv[0]);
+                       rc = MANDOCLEVEL_BADARG;
+                       goto out;
+               }
+
+               /*
+                * For standard man(1) and -a output mode,
+                * prepare for copying filename pointers
+                * into the program parameter array.
+                */
+
+               if (outmode == OUTMODE_ONE) {
+                       argc = 1;
+                       best_prio = 10;
+               } else if (outmode == OUTMODE_ALL)
+                       argc = (int)sz;
+
+               /* Iterate all matching manuals. */
+

                for (i = 0; i < sz; i++) {
                        if (outmode == OUTMODE_FLN)
                                puts(res[i].file);
                for (i = 0; i < sz; i++) {
                        if (outmode == OUTMODE_FLN)
                                puts(res[i].file);

-                       else
+                       else if (outmode == OUTMODE_LST)

                                printf("%s - %s\n", res[i].names,
                                    res[i].output == NULL ? "" :
                                    res[i].output);
                                printf("%s - %s\n", res[i].names,
                                    res[i].output == NULL ? "" :
                                    res[i].output);

+                       else if (outmode == OUTMODE_ONE) {
+                               /* Search for the best section. */
+                               isec = strcspn(res[i].file, "123456789");
+                               sec = res[i].file[isec];
+                               if ('\0' == sec)
+                                       continue;
+                               prio = sec_prios[sec - '1'];
+                               if (prio >= best_prio)
+                                       continue;
+                               best_prio = prio;
+                               resp = res + i;
+                       }

                }
                }

-               mansearch_free(res, sz);
-               mansearch_setup(0);
-               return((int)MANDOCLEVEL_OK);
+
+               /*
+                * For man(1), -a and -i output mode, fall through
+                * to the main mandoc(1) code iterating files
+                * and running the parsers on each of them.
+                */
+
+               if (outmode == OUTMODE_FLN || outmode == OUTMODE_LST)
+                       goto out;

 #else
                fputs("mandoc: database support not compiled in\n",
                    stderr);
 #else
                fputs("mandoc: database support not compiled in\n",
                    stderr);


@@ -266,7 +364,12 @@ main(int argc, char *argv[])
        if ( ! moptions(&options, auxpaths))
                return((int)MANDOCLEVEL_BADARG);
 
        if ( ! moptions(&options, auxpaths))
                return((int)MANDOCLEVEL_BADARG);
 

-       curp.mp = mparse_alloc(options, curp.wlevel, mmsg, defos);
+       if (use_pager && isatty(STDOUT_FILENO))
+               spawn_pager();
+
+       curp.mchars = mchars_alloc();
+       curp.mp = mparse_alloc(options, curp.wlevel, mmsg,
+           curp.mchars, defos);

 
        /*
         * Conditionally start up the lookaside buffer before parsing.
 
        /*
         * Conditionally start up the lookaside buffer before parsing.


@@ -274,22 +377,56 @@ main(int argc, char *argv[])
        if (OUTT_MAN == curp.outtype)
                mparse_keep(curp.mp);
 
        if (OUTT_MAN == curp.outtype)
                mparse_keep(curp.mp);
 

-       rc = MANDOCLEVEL_OK;
-
-       if (NULL == *argv)
+       if (argc == 0)

                parse(&curp, STDIN_FILENO, "<stdin>", &rc);
 
                parse(&curp, STDIN_FILENO, "<stdin>", &rc);
 

-       while (*argv) {
-               parse(&curp, -1, *argv, &rc);
+       while (argc) {
+#if HAVE_SQLITE3
+               if (resp != NULL) {
+                       rc = mparse_open(curp.mp, &fd, resp->file,
+                           &child_pid);
+                       if (fd == -1)
+                               /* nothing */;
+                       else if (resp->form & FORM_SRC) {
+                               /* For .so only; ignore failure. */
+                               chdir(paths.paths[resp->ipath]);
+                               parse(&curp, fd, resp->file, &rc);
+                       } else
+                               rc = passthrough(resp->file, fd,
+                                   synopsis_only);
+                       resp++;
+               } else
+#endif
+               {
+                       rc = mparse_open(curp.mp, &fd, *argv++,
+                           &child_pid);
+                       if (fd != -1)
+                               parse(&curp, fd, argv[-1], &rc);
+               }
+
+               if (child_pid &&
+                   mparse_wait(curp.mp, child_pid) != MANDOCLEVEL_OK)
+                       rc = MANDOCLEVEL_SYSERR;
+

                if (MANDOCLEVEL_OK != rc && curp.wstop)
                        break;
                if (MANDOCLEVEL_OK != rc && curp.wstop)
                        break;

-               ++argv;
+               argc--;

        }
 
        if (curp.outfree)
                (*curp.outfree)(curp.outdata);
        }
 
        if (curp.outfree)
                (*curp.outfree)(curp.outdata);

-       if (curp.mp)
-               mparse_free(curp.mp);
+       mparse_free(curp.mp);
+       mchars_free(curp.mchars);
+
+#if HAVE_SQLITE3
+out:
+       if (search.argmode != ARG_FILE) {
+               manpath_free(&paths);
+               mansearch_free(res, sz);
+               mansearch_setup(0);
+       }
+#endif
+

        free(defos);
 
        return((int)rc);
        free(defos);
 
        return((int)rc);


@@ -309,22 +446,23 @@ usage(enum argmode argmode)
 
        switch (argmode) {
        case ARG_FILE:
 
        switch (argmode) {
        case ARG_FILE:

-               fputs("usage: mandoc [-V] [-Ios=name] [-mformat]"
-                   " [-Ooption] [-Toutput] [-Wlevel]\n"
-                   "\t      [file ...]\n", stderr);
+               fputs("usage: mandoc [-acfhklV] [-Ios=name] "
+                   "[-Kencoding] [-mformat] [-Ooption]\n"
+                   "\t      [-Toutput] [-Wlevel] [file ...]\n", stderr);

                break;
        case ARG_NAME:
                break;
        case ARG_NAME:

-               fputs("usage: man [-acfhkVw] [-C file] "
+               fputs("usage: man [-acfhklVw] [-C file] "

                    "[-M path] [-m path] [-S arch] [-s section]\n"
                    "\t   [section] name ...\n", stderr);
                break;
        case ARG_WORD:
                    "[-M path] [-m path] [-S arch] [-s section]\n"
                    "\t   [section] name ...\n", stderr);
                break;
        case ARG_WORD:

-               fputs("usage: whatis [-V] [-C file] [-M path] [-m path] "
-                   "[-S arch] [-s section] name ...\n", stderr);
+               fputs("usage: whatis [-acfhklVw] [-C file] "
+                   "[-M path] [-m path] [-O outkey] [-S arch]\n"
+                   "\t      [-s section] name ...\n", stderr);

                break;
        case ARG_EXPR:
                break;
        case ARG_EXPR:

-               fputs("usage: apropos [-V] [-C file] [-M path] [-m path] "
-                   "[-O outkey] [-S arch]\n"
+               fputs("usage: apropos [-acfhklVw] [-C file] "
+                   "[-M path] [-m path] [-O outkey] [-S arch]\n"

                    "\t       [-s section] expression ...\n", stderr);
                break;
        }
                    "\t       [-s section] expression ...\n", stderr);
                break;
        }


@@ -363,32 +501,34 @@ parse(struct curparse *curp, int fd, const char *file,
 
        if ( ! (curp->outman && curp->outmdoc)) {
                switch (curp->outtype) {
 
        if ( ! (curp->outman && curp->outmdoc)) {
                switch (curp->outtype) {

-               case OUTT_XHTML:
-                       curp->outdata = xhtml_alloc(curp->outopts);
-                       curp->outfree = html_free;
-                       break;

                case OUTT_HTML:
                case OUTT_HTML:

-                       curp->outdata = html_alloc(curp->outopts);
+                       curp->outdata = html_alloc(curp->mchars,
+                           curp->outopts);

                        curp->outfree = html_free;
                        break;
                case OUTT_UTF8:
                        curp->outfree = html_free;
                        break;
                case OUTT_UTF8:

-                       curp->outdata = utf8_alloc(curp->outopts);
+                       curp->outdata = utf8_alloc(curp->mchars,
+                           curp->outopts);

                        curp->outfree = ascii_free;
                        break;
                case OUTT_LOCALE:
                        curp->outfree = ascii_free;
                        break;
                case OUTT_LOCALE:

-                       curp->outdata = locale_alloc(curp->outopts);
+                       curp->outdata = locale_alloc(curp->mchars,
+                           curp->outopts);

                        curp->outfree = ascii_free;
                        break;
                case OUTT_ASCII:
                        curp->outfree = ascii_free;
                        break;
                case OUTT_ASCII:

-                       curp->outdata = ascii_alloc(curp->outopts);
+                       curp->outdata = ascii_alloc(curp->mchars,
+                           curp->outopts);

                        curp->outfree = ascii_free;
                        break;
                case OUTT_PDF:
                        curp->outfree = ascii_free;
                        break;
                case OUTT_PDF:

-                       curp->outdata = pdf_alloc(curp->outopts);
+                       curp->outdata = pdf_alloc(curp->mchars,
+                           curp->outopts);

                        curp->outfree = pspdf_free;
                        break;
                case OUTT_PS:
                        curp->outfree = pspdf_free;
                        break;
                case OUTT_PS:

-                       curp->outdata = ps_alloc(curp->outopts);
+                       curp->outdata = ps_alloc(curp->mchars,
+                           curp->outopts);

                        curp->outfree = pspdf_free;
                        break;
                default:
                        curp->outfree = pspdf_free;
                        break;
                default:


@@ -397,8 +537,6 @@ parse(struct curparse *curp, int fd, const char *file,
 
                switch (curp->outtype) {
                case OUTT_HTML:
 
                switch (curp->outtype) {
                case OUTT_HTML:

-                       /* FALLTHROUGH */
-               case OUTT_XHTML:

                        curp->outman = html_man;
                        curp->outmdoc = html_mdoc;
                        break;
                        curp->outman = html_man;
                        curp->outmdoc = html_mdoc;
                        break;


@@ -444,6 +582,90 @@ parse(struct curparse *curp, int fd, const char *file,
                *level = rc;
 }
 
                *level = rc;
 }
 

+static enum mandoclevel
+passthrough(const char *file, int fd, int synopsis_only)
+{
+       const char       synb[] = "S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS";
+       const char       synr[] = "SYNOPSIS";
+
+       FILE            *stream;
+       const char      *syscall;
+       char            *line;
+       size_t           len, off;
+       ssize_t          nw;
+       int              print;
+
+       if ((stream = fdopen(fd, "r")) == NULL) {
+               close(fd);
+               syscall = "fdopen";
+               goto fail;
+       }
+
+       print = 0;
+       while ((line = fgetln(stream, &len)) != NULL) {
+               if (synopsis_only) {
+                       if (print) {
+                               if ( ! isspace((unsigned char)*line))
+                                       goto done;
+                               while (len &&
+                                   isspace((unsigned char)*line)) {
+                                       line++;
+                                       len--;
+                               }
+                       } else {
+                               if ((len == sizeof(synb) &&
+                                    ! strncmp(line, synb, len - 1)) ||
+                                   (len == sizeof(synr) &&
+                                    ! strncmp(line, synr, len - 1)))
+                                       print = 1;
+                               continue;
+                       }
+               }
+               for (off = 0; off < len; off += nw)
+                       if ((nw = write(STDOUT_FILENO, line + off,
+                           len - off)) == -1 || nw == 0) {
+                               fclose(stream);
+                               syscall = "write";
+                               goto fail;
+                       }
+       }
+
+       if (ferror(stream)) {
+               fclose(stream);
+               syscall = "fgetln";
+               goto fail;
+       }
+
+done:
+       fclose(stream);
+       return(MANDOCLEVEL_OK);
+
+fail:
+       fprintf(stderr, "%s: %s: SYSERR: %s: %s",
+           progname, file, syscall, strerror(errno));
+       return(MANDOCLEVEL_SYSERR);
+}
+
+static int
+koptions(int *options, char *arg)
+{
+
+       if ( ! strcmp(arg, "utf-8")) {
+               *options |=  MPARSE_UTF8;
+               *options &= ~MPARSE_LATIN1;
+       } else if ( ! strcmp(arg, "iso-8859-1")) {
+               *options |=  MPARSE_LATIN1;
+               *options &= ~MPARSE_UTF8;
+       } else if ( ! strcmp(arg, "us-ascii")) {
+               *options &= ~(MPARSE_UTF8 | MPARSE_LATIN1);
+       } else {
+               fprintf(stderr, "%s: -K%s: Bad argument\n",
+                   progname, arg);
+               return(0);
+       }
+       return(1);
+}
+

 static int
 moptions(int *options, char *arg)
 {
 static int
 moptions(int *options, char *arg)
 {


@@ -485,7 +707,7 @@ toptions(struct curparse *curp, char *arg)
        else if (0 == strcmp(arg, "locale"))
                curp->outtype = OUTT_LOCALE;
        else if (0 == strcmp(arg, "xhtml"))
        else if (0 == strcmp(arg, "locale"))
                curp->outtype = OUTT_LOCALE;
        else if (0 == strcmp(arg, "xhtml"))

-               curp->outtype = OUTT_XHTML;
+               curp->outtype = OUTT_HTML;

        else if (0 == strcmp(arg, "ps"))
                curp->outtype = OUTT_PS;
        else if (0 == strcmp(arg, "pdf"))
        else if (0 == strcmp(arg, "ps"))
                curp->outtype = OUTT_PS;
        else if (0 == strcmp(arg, "pdf"))


@@ -560,3 +782,79 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 
        fputc('\n', stderr);
 }
 
        fputc('\n', stderr);
 }

+
+static void
+spawn_pager(void)
+{
+#define MAX_PAGER_ARGS 16
+       char            *argv[MAX_PAGER_ARGS];
+       const char      *pager;
+       char            *cp;
+       int              fildes[2];
+       int              argc;
+
+       if (pipe(fildes) == -1) {
+               fprintf(stderr, "%s: pipe: %s\n",
+                   progname, strerror(errno));
+               return;
+       }
+
+       switch (fork()) {
+       case -1:
+               fprintf(stderr, "%s: fork: %s\n",
+                   progname, strerror(errno));
+               exit((int)MANDOCLEVEL_SYSERR);
+       case 0:
+               close(fildes[0]);
+               if (dup2(fildes[1], STDOUT_FILENO) == -1) {
+                       fprintf(stderr, "%s: dup output: %s\n",
+                           progname, strerror(errno));
+                       exit((int)MANDOCLEVEL_SYSERR);
+               }
+               return;
+       default:
+               break;
+       }
+
+       /* The original process becomes the pager. */
+
+       close(fildes[1]);
+       if (dup2(fildes[0], STDIN_FILENO) == -1) {
+               fprintf(stderr, "%s: dup input: %s\n",
+                   progname, strerror(errno));
+               exit((int)MANDOCLEVEL_SYSERR);
+       }
+
+       pager = getenv("MANPAGER");
+       if (pager == NULL || *pager == '\0')
+               pager = getenv("PAGER");
+       if (pager == NULL || *pager == '\0')
+               pager = "/usr/bin/more -s";
+       cp = mandoc_strdup(pager);
+
+       /*
+        * Parse the pager command into words.
+        * Intentionally do not do anything fancy here.
+        */
+
+       argc = 0;
+       while (argc + 1 < MAX_PAGER_ARGS) {
+               argv[argc++] = cp;
+               cp = strchr(cp, ' ');
+               if (cp == NULL)
+                       break;
+               *cp++ = '\0';
+               while (*cp == ' ')
+                       cp++;
+               if (*cp == '\0')
+                       break;
+       }
+       argv[argc] = NULL;
+
+       /* Hand over to the pager. */
+
+       execvp(argv[0], argv);
+       fprintf(stderr, "%s: exec: %s\n",
+           progname, strerror(errno));
+       exit((int)MANDOCLEVEL_SYSERR);
+}