--- name: "explain_rename" section: "3" platform: "linux" package: "libexplain-dev" version: "1.4.D001-16" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/explain_rename" --- # explain\_rename(3) explain rename(2) errors ## NAME explain\_rename - explain [rename(2)](/rename/2.md) errors ## SYNOPSIS \#include \\ const char \*explain\_rename(const char \*oldpath, const char \*newpath);\ const char \*explain\_errno\_rename(int errnum, const char \*oldpath, const char \*newpath);\ void explain\_message\_rename(char \*message, int message\_size, const char \*oldpath, const char \*newpath);\ void explain\_message\_errno\_rename(char \*message, int message\_size, int errnum, const char \*oldpath, const char \*newpath); ## DESCRIPTION The functions declared in the `` include file may be used to explain errors returned by the [*rename*(2)](/rename/2.md) system call. ### explain\_rename const char \*explain\_rename(const char \*oldpath, const char \*newpath); The explain\_rename function is used to obtain an explanation of an error returned by the [*rename*(2)](/rename/2.md) function. The least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. The *errno* global variable will be used to obtain the error value to be decoded. This function is intended to be used in a fashion similar to the following example: ``` if (rename(oldpath, rewpath) < 0) { fprintf(stderr, "%s\n", explain_rename(oldpath, newpath)); exit(EXIT_FAILURE); } ``` - *oldpath* The original oldpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. - *newpath* The original newpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. - Returns: The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads. **Note:** This function is **not** thread safe, because it shares a return buffer across all threads, and many other functions in this library. ### explain\_errno\_rename const char \*explain\_errno\_rename(int errnum, const char \*oldpath, const char \*newpath); The explain\_errno\_rename function is used to obtain an explanation of an error returned by the [rename(2)](/rename/2.md) function. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail. This function is intended to be used in a fashion similar to the following example: ``` if (rename(oldpath, newpath) < 0) { int err = errno; fprintf(stderr, "%s\n", explain_errno_rename(err, oldpath, newpath)); exit(EXIT_FAILURE); } ``` - *errnum* The error value to be decoded, usually obtained from the *errno* global variable just before this function is called. This is necessary if you need to call **any** code between the system call to be explained and this function, because many libc functions will alter the value of *errno*. - *oldpath* The original oldpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. - *newpath* The original newpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. - Returns: The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads. **Note:** This function is **not** thread safe, because it shares a return buffer across all threads, and many other functions in this library. ### explain\_message\_rename void explain\_message\_rename(char \*message, int message\_size, const char \*oldpath, const char \*newpath); The explain\_message\_rename function is used to obtain an explanation of an error returned by the [*rename*(2)](/rename/2.md) function. The least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. The *errno* global variable will be used to obtain the error value to be decoded. This function is intended to be used in a fashion similar to the following example: ``` if (rename(oldpath, newpath) < 0) { char message[3000]; explain_message_rename(message, sizeof(message), oldpath, newpath); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } ``` - *message* The location in which to store the returned message. Because a message return buffer has been supplied, this function is thread safe, if the buffer is thread safe. - *message\_size* The size in bytes of the location in which to store the returned message. - *oldpath* The original oldpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. - *newpath* The original newpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. ### explain\_message\_errno\_rename void explain\_message\_errno\_rename(char \*message, int message\_size, int errnum, const char \*oldpath, const char \*newpath); The explain\_message\_errno\_rename function is used to obtain an explanation of an error returned by the [*rename*(2)](/rename/2.md) function. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail. This function is intended to be used in a fashion similar to the following example: ``` if (rename(oldpath, newpath) < 0) { int err = errno; char message[3000]; explain_message_errno_rename(message, sizeof(message), err, oldpath, newpath); fprintf(stderr, "%s\n", message); exit(EXIT_FAILURE); } ``` - *message* The location in which to store the returned message. Because a message return buffer has been supplied, this function is thread safe, given a thread safe buffer. - *message\_size* The size in bytes of the location in which to store the returned message. - *errnum* The error value to be decoded, usually obtained from the *errno* global variable just before this function is called. This is necessary if you need to call **any** code between the system call to be explained and this function, because many libc functions will alter the value of *errno*. - *oldpath* The original oldpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. - *newpath* The original newpath, exactly as passed to the [*rename*(2)](/rename/2.md) system call. ## COPYRIGHT libexplain version 1.4\ Copyright (C) 2008 Peter Miller ## AUTHOR Written by Peter Miller \