terminology: call them null-terminated strings

Updated terminology in docs, comments and phrases to refer to C strings
as "null-terminated". Done to unify with how most other C oriented docs
refer of them and what users in general seem to prefer (based on a
single highly unscientific poll on twitter).

Reported-by: coinhubs on github
Fixes curl#5598
Closes curl#5608

docs/libcurl/curl_easy_escape.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -51,7 +51,7 @@ to the function is encoded correctly.
 .SH AVAILABILITY
 Added in 7.15.4 and replaces the old \fIcurl_escape(3)\fP function.
 .SH RETURN VALUE
-A pointer to a zero terminated string or NULL if it failed.
+A pointer to a null-terminated string or NULL if it failed.
 .SH EXAMPLE
 .nf
 CURL *curl = curl_easy_init();

docs/libcurl/curl_easy_strerror.3

@@ -35,6 +35,6 @@ specific error descriptions generated at run-time.
 .SH AVAILABILITY
 This function was added in libcurl 7.12.0
 .SH RETURN VALUE
-A pointer to a zero terminated string.
+A pointer to a null-terminated string.
 .SH "SEE ALSO"
 .BR libcurl-errors "(3), " curl_multi_strerror "(3), " curl_share_strerror "(3)"

docs/libcurl/curl_easy_unescape.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -49,6 +49,6 @@ You must \fIcurl_free(3)\fP the returned string when you're done with it.
 .SH AVAILABILITY
 Added in 7.15.4 and replaces the old \fIcurl_unescape(3)\fP function.
 .SH RETURN VALUE
-A pointer to a zero terminated string or NULL if it failed.
+A pointer to a null-terminated string or NULL if it failed.
 .SH "SEE ALSO"
 .BR curl_easy_escape "(3), " curl_free "(3)," RFC 3986

docs/libcurl/curl_escape.3

@@ -43,6 +43,6 @@ You must \fIcurl_free(3)\fP the returned string when you're done with it.
 Since 7.15.4, \fIcurl_easy_escape(3)\fP should be used. This function will
 be removed in a future release.
 .SH RETURN VALUE
-A pointer to a zero terminated string or NULL if it failed.
+A pointer to a null-terminated string or NULL if it failed.
 .SH "SEE ALSO"
 .BR curl_unescape "(3), " curl_free "(3), " RFC 2396

docs/libcurl/curl_getenv.3

@@ -38,7 +38,7 @@ This function will be removed from the public libcurl API in a near future. It
 will instead be made "available" by source code access only, and then as
 curlx_getenv().
 .SH RETURN VALUE
-A pointer to a zero terminated string or NULL if it failed to find the
+A pointer to a null-terminated string or NULL if it failed to find the
 specified name.
 .SH NOTE
 Under unix operating systems, there isn't any point in returning an allocated

docs/libcurl/curl_mime_data.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -34,7 +34,7 @@ curl_mime_data - set a mime part's body data from memory
 \fIdata\fP points to the data bytes: those are copied to the part and their
 storage may safely be reused after call.
 \fIdatasize\fP is the number of data bytes: it can be set to
-\fICURL_ZERO_TERMINATED\fP to indicate \fIdata\fP is a nul-terminated
+\fICURL_ZERO_TERMINATED\fP to indicate \fIdata\fP is a null-terminated
 character string.
 \fIpart\fP is the part's to assign contents to.
 

docs/libcurl/curl_mime_encoder.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -33,7 +33,7 @@ curl_mime_encoder() requests a mime part's content to be encoded before being
 transmitted.
 
 \fIpart\fP is the part's handle to assign an encoder.
-\fIencoding\fP is a pointer to a zero-terminated encoding scheme. It may be
+\fIencoding\fP is a pointer to a null-terminated encoding scheme. It may be
 set to NULL to disable an encoder previously attached to the part. The encoding
 scheme storage may safely be reused after this function returns.
 

docs/libcurl/curl_mime_filedata.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -35,9 +35,9 @@ data to a mime part.
 
 \fIpart\fP is the part's to assign contents to.
 
-\fIfilename\fP points to the nul-terminated file's path name. The pointer can
-be NULL to detach the previous part contents settings.  Filename storage can be
-safely be reused after this call.
+\fIfilename\fP points to the null-terminated file's path name. The pointer can
+be NULL to detach the previous part contents settings.  Filename storage can
+be safely be reused after this call.
 
 As a side effect, the part's remote file name is set to the base name of the
 given \fIfilename\fP if it is a valid named file. This can be undone or

docs/libcurl/curl_mime_filename.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -36,8 +36,8 @@ associated Content-Disposition generated header.
 
 \fIpart\fP is the part's handle to assign the remote file name to.
 
-\fIfilename\fP points to the nul-terminated file name string; it may be set to
-NULL to remove a previously attached remote file name.
+\fIfilename\fP points to the null-terminated file name string; it may be set
+to NULL to remove a previously attached remote file name.
 
 The remote file name string is copied into the part, thus the associated
 storage may safely be released or reused after call. Setting a part's file

docs/libcurl/curl_mime_name.3

@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -33,7 +33,7 @@ fields are named.
 
 \fIpart\fP is the part's handle to assign a name to.
 
-\fIname\fP points to the zero-terminated name string.
+\fIname\fP points to the null-terminated name string.
 
 The name string is copied into the part, thus the associated storage may
 safely be released or reused after call. Setting a part's name twice is valid:

docs/libcurl/curl_mime_type.3

@@ -33,7 +33,7 @@ curl_mime_type - set a mime part's content type
 
 \fIpart\fP is the part's handle to assign the content type to.
 
-\fImimetype\fP points to the nul-terminated file mime type string; it may be
+\fImimetype\fP points to the null-terminated file mime type string; it may be
 set to NULL to remove a previously attached mime type.
 
 The mime type string is copied into the part, thus the associated storage may

docs/libcurl/curl_multi_strerror.3

@@ -32,6 +32,6 @@ error code passed in the argument \fIerrornum\fP.
 .SH AVAILABILITY
 This function was added in libcurl 7.12.0
 .SH RETURN VALUE
-A pointer to a zero terminated string.
+A pointer to a null-terminated string.
 .SH "SEE ALSO"
 .BR libcurl-errors "(3), " curl_easy_strerror "(3), " curl_share_strerror "(3)"

docs/libcurl/curl_share_strerror.3

@@ -32,6 +32,6 @@ error code passed in the argument \fIerrornum\fP.
 .SH AVAILABILITY
 This function was added in libcurl 7.12.0
 .SH RETURN VALUE
-A pointer to a zero terminated string.
+A pointer to a null-terminated string.
 .SH "SEE ALSO"
 .BR libcurl-errors "(3), " curl_multi_strerror "(3), " curl_easy_strerror "(3)"

docs/libcurl/curl_unescape.3

@@ -43,6 +43,6 @@ You must \fIcurl_free(3)\fP the returned string when you're done with it.
 Since 7.15.4, \fIcurl_easy_unescape(3)\fP should be used. This function will
 be removed in a future release.
 .SH RETURN VALUE
-A pointer to a zero terminated string or NULL if it failed.
+A pointer to a null-terminated string or NULL if it failed.
 .SH "SEE ALSO"
 .br curl_easy_escape "(3)," curl_easy_unescape "(3)," curl_free "(3)," RFC 2396

docs/libcurl/curl_url_set.3

@@ -35,7 +35,7 @@ Given the \fIurl\fP handle of an already parsed URL, this function lets the
 user set/update individual pieces of it.
 
 The \fIpart\fP argument should identify the particular URL part (see list
-below) to set or change, with \fIcontent\fP pointing to a zero terminated
+below) to set or change, with \fIcontent\fP pointing to a null-terminated
 string with the new contents for that URL part. The contents should be in the
 form and encoding they'd use in a URL: URL encoded.
 
@@ -51,7 +51,7 @@ populated with a URL, the new URL can be relative to the previous.
 When successfully setting a new URL, relative or absolute, the handle contents
 will be replaced with the information of the newly set URL.
 
-Pass a pointer to a zero terminated string to the \fIurl\fP parameter. The
+Pass a pointer to a null-terminated string to the \fIurl\fP parameter. The
 string must point to a correctly formatted "RFC 3986+" URL or be a NULL
 pointer.
 .IP CURLUPART_SCHEME

docs/libcurl/curl_version.3

@@ -33,7 +33,7 @@ its important components (like OpenSSL version).
 
 We recommend using \fIcurl_version_info(3)\fP instead!
 .SH RETURN VALUE
-A pointer to a zero terminated string. The string resides in a statically
+A pointer to a null-terminated string. The string resides in a statically
 allocated buffer and must not be freed by the caller.
 .SH "SEE ALSO"
 .BR curl_version_info "(3)"

docs/libcurl/opts/CURLINFO_LOCAL_IP.3

@@ -28,7 +28,7 @@ CURLINFO_LOCAL_IP \- get local IP address of last connection
 
 CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_LOCAL_IP, char **ip);
 .SH DESCRIPTION
-Pass a pointer to a char pointer to receive the pointer to a zero-terminated
+Pass a pointer to a char pointer to receive the pointer to a null-terminated
 string holding the IP address of the local end of most recent connection done
 with this \fBcurl\fP handle. This string may be IPv6 when that is
 enabled. Note that you get a pointer to a memory area that will be re-used at

docs/libcurl/opts/CURLINFO_PRIMARY_IP.3

@@ -28,7 +28,7 @@ CURLINFO_PRIMARY_IP \- get IP address of last connection
 
 CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PRIMARY_IP, char **ip);
 .SH DESCRIPTION
-Pass a pointer to a char pointer to receive the pointer to a zero-terminated
+Pass a pointer to a char pointer to receive the pointer to a null-terminated
 string holding the IP address of the most recent connection done with this
 \fBcurl\fP handle. This string may be IPv6 when that is enabled. Note that you
 get a pointer to a memory area that will be re-used at next request so you

docs/libcurl/opts/CURLINFO_SCHEME.3

@@ -28,7 +28,7 @@ CURLINFO_SCHEME \- get the URL scheme (sometimes called protocol) used in the co
 
 CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_SCHEME, char **scheme);
 .SH DESCRIPTION
-Pass a pointer to a char pointer to receive the pointer to a zero-terminated
+Pass a pointer to a char pointer to receive the pointer to a null-terminated
 string holding the URL scheme used for the most recent connection done with
 this CURL \fBhandle\fP.
 

docs/libcurl/opts/CURLOPT_ABSTRACT_UNIX_SOCKET.3

@@ -29,7 +29,7 @@ CURLOPT_ABSTRACT_UNIX_SOCKET \- set an abstract Unix domain socket
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ABSTRACT_UNIX_SOCKET, char *path);
 .SH DESCRIPTION
 Enables the use of an abstract Unix domain socket instead of establishing a TCP
-connection to a host. The parameter should be a char * to a zero terminated string
+connection to a host. The parameter should be a char * to a null-terminated string
 holding the path of the socket. The path will be set to \fIpath\fP prefixed by a
 NULL byte (this is the convention for abstract sockets, however it should be stressed
 that the path passed to this function should not contain a leading NULL).

docs/libcurl/opts/CURLOPT_CAINFO.3

@@ -28,7 +28,7 @@ CURLOPT_CAINFO \- path to Certificate Authority (CA) bundle
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAINFO, char *path);
 .SH DESCRIPTION
-Pass a char * to a zero terminated string naming a file holding one or more
+Pass a char * to a null-terminated string naming a file holding one or more
 certificates to verify the peer with.
 
 If \fICURLOPT_SSL_VERIFYPEER(3)\fP is zero and you avoid verifying the

docs/libcurl/opts/CURLOPT_CAPATH.3

@@ -28,7 +28,7 @@ CURLOPT_CAPATH \- specify directory holding CA certificates
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAPATH, char *capath);
 .SH DESCRIPTION
-Pass a char * to a zero terminated string naming a directory holding multiple
+Pass a char * to a null-terminated string naming a directory holding multiple
 CA certificates to verify the peer with. If libcurl is built against OpenSSL,
 the certificate directory must be prepared using the openssl c_rehash utility.
 This makes sense only when used in combination with the

docs/libcurl/opts/CURLOPT_COOKIE.3

@@ -28,7 +28,7 @@ CURLOPT_COOKIE \- set contents of HTTP Cookie header
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_COOKIE, char *cookie);
 .SH DESCRIPTION
-Pass a pointer to a zero terminated string as parameter. It will be used to
+Pass a pointer to a null-terminated string as parameter. It will be used to
 set a cookie in the HTTP request. The format of the string should be
 NAME=CONTENTS, where NAME is the cookie name and CONTENTS is what the cookie
 should contain.

docs/libcurl/opts/CURLOPT_COOKIEFILE.3

@@ -28,7 +28,7 @@ CURLOPT_COOKIEFILE \- file name to read cookies from
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_COOKIEFILE, char *filename);
 .SH DESCRIPTION
-Pass a pointer to a zero terminated string as parameter. It should point to
+Pass a pointer to a null-terminated string as parameter. It should point to
 the file name of your file holding cookie data to read. The cookie data can be
 in either the old Netscape / Mozilla cookie data format or just regular HTTP
 headers (Set-Cookie style) dumped to a file.

docs/libcurl/opts/CURLOPT_COOKIEJAR.3

@@ -28,7 +28,7 @@ CURLOPT_COOKIEJAR \- file name to store cookies to
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_COOKIEJAR, char *filename);
 .SH DESCRIPTION
-Pass a \fIfilename\fP as char *, zero terminated. This will make libcurl write
+Pass a \fIfilename\fP as char *, null-terminated. This will make libcurl write
 all internally known cookies to the specified file when
 \fIcurl_easy_cleanup(3)\fP is called. If no cookies are known, no file will be
 created. Specify "-" as filename to instead have the cookies written to

docs/libcurl/opts/CURLOPT_COPYPOSTFIELDS.3

@@ -36,7 +36,7 @@ to overwrite the original data after setting this option.
 Because data are copied, care must be taken when using this option in
 conjunction with \fICURLOPT_POSTFIELDSIZE(3)\fP or
 \fICURLOPT_POSTFIELDSIZE_LARGE(3)\fP: If the size has not been set prior to
-\fICURLOPT_COPYPOSTFIELDS(3)\fP, the data is assumed to be a zero terminated
+\fICURLOPT_COPYPOSTFIELDS(3)\fP, the data is assumed to be a null-terminated
 string; else the stored size informs the library about the byte count to
 copy. In any case, the size must not be changed after
 \fICURLOPT_COPYPOSTFIELDS(3)\fP, unless another \fICURLOPT_POSTFIELDS(3)\fP or

docs/libcurl/opts/CURLOPT_CRLFILE.3

@@ -28,7 +28,7 @@ CURLOPT_CRLFILE \- specify a Certificate Revocation List file
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CRLFILE, char *file);
 .SH DESCRIPTION
-Pass a char * to a zero terminated string naming a \fIfile\fP with the
+Pass a char * to a null-terminated string naming a \fIfile\fP with the
 concatenation of CRL (in PEM format) to use in the certificate validation that
 occurs during the SSL exchange.
 

docs/libcurl/opts/CURLOPT_CUSTOMREQUEST.3

@@ -28,7 +28,7 @@ CURLOPT_CUSTOMREQUEST \- custom string for request
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CUSTOMREQUEST, char *request);
 .SH DESCRIPTION
-Pass a pointer to a zero terminated string as parameter.
+Pass a pointer to a null-terminated string as parameter.
 
 When you change the request method by setting \fICURLOPT_CUSTOMREQUEST(3)\fP
 to something, you don't actually change how libcurl behaves or acts in regards

docs/libcurl/opts/CURLOPT_DEBUGFUNCTION.3

@@ -54,7 +54,7 @@ shown above.
 \fICURLOPT_VERBOSE(3)\fP is in effect. This callback receives debug
 information, as specified in the \fItype\fP argument. This function must
 return 0. The \fIdata\fP pointed to by the char * passed to this function WILL
-NOT be zero terminated, but will be exactly of the \fIsize\fP as told by the
+NOT be null-terminated, but will be exactly of the \fIsize\fP as told by the
 \fIsize\fP argument.
 
 The \fIuserptr\fP argument is the pointer set with \fICURLOPT_DEBUGDATA(3)\fP.

docs/libcurl/opts/CURLOPT_DOH_URL.3

@@ -29,7 +29,7 @@ CURLOPT_DOH_URL \- provide the DNS-over-HTTPS URL
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_URL, char *URL);
 .SH DESCRIPTION
 Pass in a pointer to a \fIURL\fP for the DOH server to use for name
-resolving. The parameter should be a char * to a zero terminated string which
+resolving. The parameter should be a char * to a null-terminated string which
 must be URL-encoded in the following format: "https://host:port/path". It MUST
 specify a HTTPS URL.
 

docs/libcurl/opts/CURLOPT_EGDSOCKET.3

@@ -28,7 +28,7 @@ CURLOPT_EGDSOCKET \- set EGD socket path
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_EGDSOCKET, char *path);
 .SH DESCRIPTION
-Pass a char * to the zero terminated path name to the Entropy Gathering Daemon
+Pass a char * to the null-terminated path name to the Entropy Gathering Daemon
 socket. It will be used to seed the random engine for SSL.
 
 The application does not have to keep the string around after setting this

docs/libcurl/opts/CURLOPT_FTPPORT.3

@@ -28,7 +28,7 @@ CURLOPT_FTPPORT \- make FTP transfer active
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTPPORT, char *spec);
 .SH DESCRIPTION
-Pass a pointer to a zero terminated string as parameter. It specifies that the
+Pass a pointer to a null-terminated string as parameter. It specifies that the
 FTP transfer will be made actively and the given string will be used to get
 the IP address to use for the FTP PORT instruction.
 

docs/libcurl/opts/CURLOPT_FTP_ACCOUNT.3

@@ -28,7 +28,7 @@ CURLOPT_FTP_ACCOUNT \- set account info for FTP
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_ACCOUNT, char *account);
 .SH DESCRIPTION
-Pass a pointer to a zero terminated string (or NULL to disable). When an FTP
+Pass a pointer to a null-terminated string (or NULL to disable). When an FTP
 server asks for "account data" after user name and password has been provided,
 this data is sent off using the ACCT command.
 

docs/libcurl/opts/CURLOPT_HEADERFUNCTION.3

@@ -41,7 +41,7 @@ data. The header callback will be called once for each header and only
 complete header lines are passed on to the callback. Parsing headers is very
 easy using this. \fIbuffer\fP points to the delivered data, and the size of
 that data is \fInitems\fP; \fIsize\fP is always 1. Do not assume that the
-header line is zero terminated!
+header line is null-terminated!
 
 The pointer named \fIuserdata\fP is the one you set with the
 \fICURLOPT_HEADERDATA(3)\fP option.

docs/libcurl/opts/CURLOPT_ISSUERCERT.3

@@ -28,7 +28,7 @@ CURLOPT_ISSUERCERT \- issuer SSL certificate filename
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ISSUERCERT, char *file);
 .SH DESCRIPTION
-Pass a char * to a zero terminated string naming a \fIfile\fP holding a CA
+Pass a char * to a null-terminated string naming a \fIfile\fP holding a CA
 certificate in PEM format. If the option is set, an additional check against
 the peer certificate is performed to verify the issuer is indeed the one
 associated with the certificate provided by the option. This additional check