get_long.3

'\" t
.\"     Title: get_long
.\"    Author: [see the "AUTHOR(S)" section]
.\" Generator: Asciidoctor 1.5.7.1
.\"      Date: 2017-09-16
.\"    Manual: CS50 Programmer's Manual
.\"    Source: CS50
.\"  Language: English
.\"
.TH "GET_LONG" "3" "2017-09-16" "CS50" "CS50 Programmer\(aqs Manual"
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.SH "NAME"
get_long \- prompts user for a line of text from stdin and returns the equivalent long
.SH "SYNOPSIS"
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\fB#include <cs50.h>\fP
.sp
\fBlong get_long(const char *format, ...);\fP
.SH "DESCRIPTION"
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Prompts user for a line of text from standard input and returns the equivalent long; if the text does not represent a long or would cause overflow, user is reprompted.
.sp
The prompt is formatted like \fBprintf(3)\fP.
.SH "RETURN VALUE"
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Returns the long equivalent to the line read from stdin in [\fBLONG_MIN\fP, \fBLONG_MAX\fP). If line can\(cqt be read, returns \fBLONG_MAX\fP.
.SH "EXAMPLE"
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/**
 * Returns the difference of two longs read from stdin, or LONG_MAX if there was an error.
 */
long subtract_longs(void)
{
    // read long from stdin
    long i = get_long("Enter a long: ");

    // make sure we read one successfully
    if (i == LONG_MAX)
    {
        return LONG_MAX;
    }

    long j = get_long("What do you want to subtract from %ld? ", i);

    if (j == LONG_MAX)
    {
        return LONG_MAX;
    }

    return i \- j;
}
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.SH "SEE ALSO"
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get_char(3), get_double(3), get_float(3), get_int(3), get_string(3),
printf(3)
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