diff options
Diffstat (limited to 'stand/libsa/pager.c')
| -rw-r--r-- | stand/libsa/pager.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/stand/libsa/pager.c b/stand/libsa/pager.c new file mode 100644 index 000000000000..a966b0bd7992 --- /dev/null +++ b/stand/libsa/pager.c @@ -0,0 +1,161 @@ +/*- + * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> + * 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. + */ +/* + * Simple paged-output and paged-viewing functions + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "stand.h" +#include <string.h> + +static int p_maxlines = -1; +static int p_freelines; + +static char *pager_prompt1 = " --more-- <space> page down <enter> line down <q> 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("%s", 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); + } + + 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; + } + } + close(fd); + return(result); +} |