string.h 没有手动输入

Question

我试图找到“string.h”的手动条目，我安装了 GNU gcc。但是当我输入时man string.h，它显示我no manual entry for string.h，我不确定出了什么问题？有人可以帮我吗？谢谢！

Answer 1

使用man man，我们可以看到手册页分为以下部分：

   1   Executable programs or shell commands
   2   System calls (functions provided by the kernel)
   3   Library calls (functions within program libraries)
   4   Special files (usually found in /dev)
   5   File formats and conventions eg /etc/passwd
   6   Games
   7   Miscellaneous  (including  macro  packages  and  conventions), e.g.
       man(7), groff(7)
   8   System administration commands (usually only for root)
   9   Kernel routines [Non standard]

请注意，第 3 节是为了functions within program librariesie 它通常是记录的单个函数，而不是特定的头文件。例如man strncpy：

STRCPY(3)                  Linux Programmer's Manual                 STRCPY(3)

NAME
       strcpy, strncpy - copy a string

SYNOPSIS
       #include <string.h>

       char *strcpy(char *dest, const char *src);

       char *strncpy(char *dest, const char *src, size_t n);

DESCRIPTION
       The  strcpy()  function  copies the string pointed to by src, including
       the terminating null byte ('\0'), to the buffer  pointed  to  by  dest.
       The  strings  may  not overlap, and the destination string dest must be
       large enough to receive the copy.  Beware  of  buffer  overruns!   (See
       BUGS.)
etc.

在这种情况下，有一个概述man string（就像 for stdio- 但显然不是 for stdlib）

STRING(3)                  Linux Programmer's Manual                 STRING(3)

NAME
       stpcpy,  strcasecmp,  strcat, strchr, strcmp, strcoll, strcpy, strcspn,
       strdup, strfry, strlen, strncat, strncmp, strncpy,  strncasecmp,  strp?
       brk,  strrchr, strsep, strspn, strstr, strtok, strxfrm, index, rindex -
       string operations

SYNOPSIS
       #include <strings.h>
etc.

注意不要与 目录第 (1) 节中man strings的strings命令行实用程序的哪个文档混淆。