/*- * Copyright (c) 1998 Michael Smith * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $Id: pager.c,v 1.1.1.1 1998/08/20 08:19:55 msmith Exp $ */ /* * Simple paged-output and paged-viewing functions */ #include "stand.h" #include static int p_maxlines = -1; static int p_freelines; static char *pager_prompt1 = " --more-- page down line down quit "; static char *pager_blank = " "; /* * 'open' the pager */ void pager_open(void) { int nlines; char *cp, *lp; nlines = 24; /* sensible default */ if ((cp = getenv("LINES")) != NULL) { nlines = strtol(cp, &lp, 0); } p_maxlines = nlines - 1; if (p_maxlines < 1) p_maxlines = 1; p_freelines = p_maxlines; } /* * 'close' the pager */ void pager_close(void) { p_maxlines = -1; } /* * Emit lines to the pager; may not return until the user * has responded to the prompt. * * Will return nonzero if the user enters 'q' or 'Q' at the prompt. * * XXX note that this watches outgoing newlines (and eats them), but * does not handle wrap detection (req. count of columns). */ int pager_output(const char *cp) { int action; if (cp == NULL) return(0); for (;;) { if (*cp == 0) return(0); putchar(*cp); /* always emit character */ if (*(cp++) == '\n') { /* got a newline? */ p_freelines--; if (p_freelines <= 0) { printf(pager_prompt1); action = 0; while (action == 0) { switch(getchar()) { case '\r': case '\n': p_freelines = 1; action = 1; break; case ' ': p_freelines = p_maxlines; action = 1; break; case 'q': case 'Q': action = 2; break; default: break; } } printf("\r%s\r", pager_blank); if (action == 2) return(1); } } } } /* * Display from (fd). */ int pager_file(const char *fname) { char buf[80]; size_t hmuch; int fd; int result; if ((fd = open(fname, O_RDONLY)) == -1) { printf("can't open '%s': %s\n", fname, strerror(errno)); return(-1); } pager_open(); for (;;) { hmuch = read(fd, buf, sizeof(buf) - 1); if (hmuch == -1) { result = -1; break; } if (hmuch == 0) { result = 0; break; } buf[hmuch] = 0; if (pager_output(buf)) { result = 1; break; } } pager_close(); close(fd); return(result); }