1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Copyright (c) 2015 by Delphix. All rights reserved.
29 * Copyright 2017 Joyent, Inc.
30 */
31
32 #ifndef _OFMT_H
33 #define _OFMT_H
34
35 /*
36 * Data structures and routines for printing output.
37 *
38 * All output is assumed to be in a columnar format, where each column
39 * represents a field to be printed out. Multiple fields in parsable output
40 * are separated by ':', with the ':' character itself escaped by a \
41 * (e.g., IPv6 addresses may be printed as "fe80\:\:1"); single field output
42 * is printed as-is.
43 * In multiline mode, every [field,value] pair is printed in a line of
44 * its own, thus: "field: value".
45 *
46 * The caller must open a handle for each set of fields to be printed by
47 * invoking ofmt_open(). The invocation to ofmt_open must provide the list of
48 * supported fields, along with formatting information (e.g., field width), and
49 * a pointer to a callback function that can provide a string representation of
50 * the value to be printed out. The set of supported fields must be a NULL
51 * terminated array of type ofmt_field_t *ofields[]. The contents of the
52 * ofmt_field_t structure are used to construct the string that is emitted by
53 * ofmt_print(), and the interpretation of these contents is described with the
54 * semantics of ofmt_print() below.
55 *
56 * In addition, the call to ofmt_open() should provide a comma-separated
57 * list of the fields, char *fields_str, that have been selected for output
58 * (typically the string passed to -o in the command-line). The caller may
59 * also specify machine-parsable mode by specifying OFMT_PARSABLE in the oflags
60 * argument. Specifying a null or empty fields_str in the machine-parsable mode
61 * will result in a returned error value of OFMT_EPARSENONE. An attempt to
62 * create a handle in machine-parsable mode with the fields_str set to "all"
63 * will result in a returned error value of OFMT_EPARSEALL. In human-friendly
64 * (non machine-parsable) mode, a NULL fields_str, or a value of "all" for
65 * fields_str, is treated as a request to print all allowable fields that fit
66 * other applicable constraints.
67 * To achieve multiline mode, OFMT_MULTILINE needs to be specified in oflags.
68 * Specifying both OFMT_MULTILINE and OFMT_PARSABLE will result in
69 * OFMT_EPARSEMULTI.
70 *
71 * Thus a typical invocation to open the ofmt_handle would be:
72 *
73 * ofmt_handle_t ofmt;
74 * ofmt_status_t ofmt_err;
75 *
76 * ofmt_err = ofmt_open(fields_str, ofields, oflags, maxcols, &ofmt);
77 *
78 * where ofields is an array of the form:
79 *
80 * static ofmt_field_t ofields[] = {
81 * {<name>, <field width>, <id>, <callback> },
82 * :
83 * {<name>, <field width>, <id>, <callback> },
84 * {NULL, 0, 0, NULL}}
85 *
86 * <callback> is the application-specified function that provides a string
87 * representation of the value to be printed for the field. The calling
88 * application may provide unique values of <id> that will be passed back to
89 * <callback>, allowing a single <callback> to be shared between multiple
90 * fields in ofields[] with the value of <id> identifying the field that
91 * triggers the callback.
92 *
93 * If successful, ofmt_open() will return OFMT_SUCCESS, with a non-null
94 * ofmt_handle. The function returns a failure code otherwise, and more
95 * information about the type of failure can be obtained by calling
96 * ofmt_strerror()
97 *
98 * In order to print a row of output, the calling application should invoke
99 *
100 * ofmt_print(ofmt_handle, cbarg);
101 *
102 * where 'cbarg' points at the arguments to be passed to the <callback>
103 * function for each column in the row. The call to ofmt_print() will then
104 * result in the <callback> function of each selected field from ofields[]
105 * invoked with cbarg embedded in the ofmt_arg as
106 *
107 * (*callback)(ofmt_arg_t *ofmt_arg, char *buf, uint_t bufsize)
108 *
109 * Columns selected for output are identified by a match between the of_name
110 * value in the ofmt_field_t and the fields_str requested. For each selected
111 * column, the callback function (*of_cb)() is invoked, and is passed the of_id
112 * value from the ofmt_field_t structure for the field.
113 *
114 * The interpretation of the of_id field is completely private to the caller,
115 * and can be optionally used by the callback function as a cookie
116 * to identify the field being printed when a single callback function is
117 * shared between multiple ofmt_field_t entries.
118 *
119 * The callback function should fill `buf' with the string to be printed for
120 * the field using the data in cbarg.
121 *
122 * The calling application should invoke ofmt_close(ofmt_handle) to free up any
123 * resources allocated for the handle after all printing is completed.
124 *
125 * The printing library computes the current size of the output window when the
126 * handle is first created. If the caller wishes to adjust the window size
127 * after the handle has been created (e.g., on the reception of SIGWINCH by the
128 * caller), the function ofmt_update_winsize(handle) may be called.
129 */
130
131 #ifdef __cplusplus
132 extern "C" {
133 #endif
134
135 #include <sys/types.h>
136
137 /*
138 * Recommended buffer size for buffers passed, for example, to ofmt_strerror().
139 */
140 #define OFMT_BUFSIZE 256
141
142 typedef enum {
143 OFMT_SUCCESS = 0,
144 OFMT_ENOMEM, /* out of memory */
145 OFMT_EBADFIELDS, /* one or more bad fields with good fields */
146 OFMT_ENOFIELDS, /* no valid output fields */
147 OFMT_EPARSEALL, /* 'all' invalid in parsable mode */
148 OFMT_EPARSENONE, /* output fields missing in parsable mode */
149 OFMT_EPARSEWRAP, /* parsable mode incompatible with wrap mode */
150 OFMT_ENOTEMPLATE, /* no template provided for fields */
151 OFMT_EPARSEMULTI /* parsable and multiline don't mix */
152 } ofmt_status_t;
153
154 /*
155 * The callback function for each field is invoked with a pointer to the
156 * ofmt_arg_t structure that contains the <id> registered by the application
157 * for that field, and the cbarg used by the application when invoking
158 * ofmt_output().
159 */
160 typedef struct ofmt_arg_s {
161 uint_t ofmt_id;
162 uint_t ofmt_width;
163 uint_t ofmt_index;
164 void *ofmt_cbarg;
165 } ofmt_arg_t;
166
167 /*
168 * ofmt callback function that provides a string representation of the value to
169 * be printed for the field.
170 */
171 typedef boolean_t ofmt_cb_t(ofmt_arg_t *, char *, uint_t);
172 typedef struct ofmt_field_s {
173 char *of_name; /* column name */
174 uint_t of_width; /* output column width */
175 uint_t of_id; /* implementation specific cookie */
176 ofmt_cb_t *of_cb; /* callback function defined by caller */
177 } ofmt_field_t;
178
179 /*
180 * ofmt_open() must be called to create the ofmt_handle_t; Resources allocated
181 * for the handle are freed by ofmt_close();
182 */
183 typedef struct ofmt_state_s *ofmt_handle_t;
184 extern ofmt_status_t ofmt_open(const char *, const ofmt_field_t *, uint_t,
185 uint_t, ofmt_handle_t *);
186
187 #define OFMT_PARSABLE 0x00000001 /* machine parsable mode */
188 #define OFMT_WRAP 0x00000002 /* wrap output if field width is exceeded */
189 #define OFMT_MULTILINE 0x00000004 /* "long" output: "name: value" lines */
190 #define OFMT_RIGHTJUST 0x00000008 /* right justified output */
191 #define OFMT_NOHEADER 0x00000010 /* do not automatically print header lines */
192
193 /*
194 * ofmt_close() must be called to free resources associated
195 * with the ofmt_handle_t
196 */
197 extern void ofmt_close(ofmt_handle_t);
198
199 /*
200 * Set the field separator used in parsable output (default is ':').
201 */
202 extern void ofmt_set_fs(ofmt_handle_t, char);
203
204 /*
205 * ofmt_print() emits one row of output
206 */
207 extern void ofmt_print(ofmt_handle_t, void *);
208
209 /*
210 * ofmt_print_header() prints the header line. It can be used with
211 * OFMT_NOHEADER to control exactly when the header gets printed.
212 */
213 extern void ofmt_print_header(ofmt_handle_t);
214
215 /*
216 * ofmt_update_winsize() updates the window size information for ofmt_handle_t
217 */
218 extern void ofmt_update_winsize(ofmt_handle_t);
219
220 /*
221 * ofmt_strerror() provides error diagnostics in the buffer that it is passed.
222 */
223 extern char *ofmt_strerror(ofmt_handle_t, ofmt_status_t, char *, uint_t);
224
225 extern void ofmt_check(ofmt_status_t oferr, boolean_t parsable,
226 ofmt_handle_t ofmt,
227 void (*die)(const char *, ...), void (*warn)(const char *, ...));
228
229 #ifdef __cplusplus
230 }
231 #endif
232
233 #endif /* _OFMT_H */