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 */ 234