| <head> |
| <title>atof(3) - Plan 9 from User Space</title> |
| <meta content="text/html; charset=utf-8" http-equiv=Content-Type> |
| </head> |
| <body bgcolor=#ffffff> |
| <table border=0 cellpadding=0 cellspacing=0 width=100%> |
| <tr height=10><td> |
| <tr><td width=20><td> |
| <tr><td width=20><td><b>ATOF(3)</b><td align=right><b>ATOF(3)</b> |
| <tr><td width=20><td colspan=2> |
| <br> |
| <p><font size=+1><b>NAME </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| atof, atoi, atol, atoll, charstod, strtod, strtol, strtoll, strtoul, |
| strtoull – convert text to numbers<br> |
| |
| </table> |
| <p><font size=+1><b>SYNOPSIS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>#include <u.h><br> |
| #include <libc.h> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>double atof(char *nptr)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>int atoi(char *nptr)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>long atol(char *nptr)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>vlong atoll(char *nptr)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>double charstod(int (*f)(void *), void *a)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>double strtod(char *nptr, char **rptr)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>long strtol(char *nptr, char **rptr, int base)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>vlong strtoll(char *nptr, char **rptr, int base)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>ulong strtoul(char *nptr, char **rptr, int base)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| </font></tt> |
| <tt><font size=+1>vlong strtoull(char *nptr, char **rptr, int base)<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>DESCRIPTION </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <i>Atof</i>, <i>atoi</i>, <i>atol</i>, and <i>atoll</i> convert a string pointed to by <i>nptr</i> |
| to floating, integer, long integer, and long long integer (<tt><font size=+1>vlong</font></tt>) |
| representation respectively. The first unrecognized character |
| ends the string. Leading C escapes are understood, as in <i>strtol</i> |
| with <i>base</i> zero (described below). |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Atof</i> recognizes an optional string of tabs and spaces, then an |
| optional sign, then a string of digits optionally containing a |
| decimal point, then an optional <tt><font size=+1>e</font></tt> or <tt><font size=+1>E</font></tt> followed by an optionally |
| signed integer. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Atoi</i> and <i>atol</i> recognize an optional string of tabs and spaces, |
| then an optional sign, then a string of decimal digits. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Strtod</i>, <i>strtol</i>, <i>strtoll</i>, <i>strtoul</i>, and <i>strtoull</i> behave similarly |
| to <i>atof</i> and <i>atol</i> and, if <i>rptr</i> is not zero, set <i>*rptr</i> to point |
| to the input character immediately after the string converted. |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Strtol</i>, <i>strtoll</i>, <i>strtoul</i>, and <i>strtoull</i> interpret the digit string |
| in the specified <i>base</i>, from 2 to 36, each digit being less than |
| the base. Digits with value over 9 are represented by letters, |
| a-z or A-Z. If <i>base</i> is 0, the input is interpreted as an integral |
| constant in the style of C (with no suffixed type indicators): |
| numbers are |
| octal if they begin with <tt><font size=+1>0</font></tt>, hexadecimal if they begin with <tt><font size=+1>0x</font></tt> |
| or <tt><font size=+1>0X</font></tt>, otherwise decimal. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Charstod</i> interprets floating point numbers in the manner of <i>atof</i>, |
| but gets successive characters by calling <tt><font size=+1>(*</font></tt><i>f</i><tt><font size=+1>)(a)</font></tt>. The last call |
| to <i>f</i> terminates the scan, so it must have returned a character |
| that is not a legal continuation of a number. Therefore, it may |
| be necessary to back up the input stream one character after |
| calling <i>charstod</i>.<br> |
| |
| </table> |
| <p><font size=+1><b>SOURCE </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <tt><font size=+1>/usr/local/plan9/src/lib9<br> |
| </font></tt> |
| </table> |
| <p><font size=+1><b>SEE ALSO </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <a href="../man3/fscanf.html"><i>fscanf</i>(3)</a><br> |
| |
| </table> |
| <p><font size=+1><b>DIAGNOSTICS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| Zero is returned if the beginning of the input string is not interpretable |
| as a number; even in this case, <i>rptr</i> will be updated.<br> |
| These routines set <i>errstr</i>.<br> |
| |
| </table> |
| <p><font size=+1><b>BUGS </b></font><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <i>Atoi</i> and <i>atol</i> accept octal and hexadecimal numbers in the style |
| of C, contrary to the ANSI specification. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Atof</i>, <i>strtod</i>, <i>strtol</i>, <i>strtoul</i>, <i>strtoll</i>, and <i>strtoull</i> are not provided: |
| they are expected to be provided by the underlying system. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Because they are implemented in the fmt library, <i>charstod</i> and |
| <i>strtod</i> are preprocessor macros defined as <i>fmtcharstod</i> and <i>fmtstrtod</i>. |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| To avoid name conflicts with the underlying system, <i>atoi</i>, <i>atol</i>, |
| and <i>atoll</i> are preprocessor macros defined as <i>p9atoi</i>, <i>p9atol</i>, and |
| <i>p9atoll</i>; see <a href="../man3/intro.html"><i>intro</i>(3)</a>.<br> |
| |
| </table> |
| |
| <td width=20> |
| <tr height=20><td> |
| </table> |
| <!-- TRAILER --> |
| <table border=0 cellpadding=0 cellspacing=0 width=100%> |
| <tr height=15><td width=10><td><td width=10> |
| <tr><td><td> |
| <center> |
| <a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a> |
| </center> |
| </table> |
| <!-- TRAILER --> |
| </body></html> |
