[unix-history] / usr / man / man3 / string.3

.TH STRING 3  "19 January 1983"
.UC 4
.SH NAME
strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, index, rindex \- string operations
.SH SYNOPSIS
.nf
.B #include <strings.h>
.PP
.B char *strcat(s1, s2)
.B char *s1, *s2;
.PP
.B char *strncat(s1, s2, n)
.B char *s1, *s2;
.PP
.B strcmp(s1, s2)
.B char *s1, *s2;
.PP
.B strncmp(s1, s2, n)
.B char *s1, *s2;
.PP
.B char *strcpy(s1, s2)
.B char *s1, *s2;
.PP
.B char *strncpy(s1, s2, n)
.B char *s1, *s2;
.PP
.B strlen(s)
.B char *s;
.PP
.B char *index(s, c)
.B char *s, c;
.PP
.B char *rindex(s, c)
.B char *s, c;
.fi
.SH DESCRIPTION
These functions operate on null-terminated strings.
They do not check for overflow of any receiving string.
.PP
.I Strcat
appends a copy of string
.I s2
to the end of string
.IR s1 .
.I Strncat
copies at most
.I n
characters.  Both return a pointer to the null-terminated result.
.PP
.I Strcmp
compares its arguments and returns an integer
greater than, equal to, or less than 0, according as
.I s1
is lexicographically greater than, equal to, or less than
.IR s2 .
.I Strncmp
makes the same comparison but looks at at most
.I n
characters.
.PP
.I Strcpy
copies string
.I s2
to
.I s1,
stopping after the null character has been moved.
.I Strncpy
copies exactly
.I n
characters, truncating or null-padding
.I s2;
the target may not be null-terminated if the length of
.I s2
is
.I n
or more.  Both return
.IR s1 .
.PP
.I Strlen
returns the number of non-null characters in
.IR s .
.PP
.I Index
.RI ( rindex )
returns a pointer to the first (last) occurrence of character 
.I c
in string
.I s,
or zero if
.I c
does not occur in  the string.
Commit	Line	Data
6a5edc3d C	1	.TH STRING 3 "19 January 1983"
	2	.UC 4
	3	.SH NAME
	4	strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, index, rindex \- string operations
	5	.SH SYNOPSIS
	6	.nf
	7	.B #include <strings.h>
	8	.PP
	9	.B char *strcat(s1, s2)
	10	.B char s1, s2;
	11	.PP
	12	.B char *strncat(s1, s2, n)
	13	.B char s1, s2;
	14	.PP
	15	.B strcmp(s1, s2)
	16	.B char s1, s2;
	17	.PP
	18	.B strncmp(s1, s2, n)
	19	.B char s1, s2;
	20	.PP
	21	.B char *strcpy(s1, s2)
	22	.B char s1, s2;
	23	.PP
	24	.B char *strncpy(s1, s2, n)
	25	.B char s1, s2;
	26	.PP
	27	.B strlen(s)
	28	.B char *s;
	29	.PP
	30	.B char *index(s, c)
	31	.B char *s, c;
	32	.PP
	33	.B char *rindex(s, c)
	34	.B char *s, c;
	35	.fi
	36	.SH DESCRIPTION
	37	These functions operate on null-terminated strings.
	38	They do not check for overflow of any receiving string.
	39	.PP
	40	.I Strcat
	41	appends a copy of string
	42	.I s2
	43	to the end of string
	44	.IR s1 .
	45	.I Strncat
	46	copies at most
	47	.I n
	48	characters. Both return a pointer to the null-terminated result.
	49	.PP
	50	.I Strcmp
	51	compares its arguments and returns an integer
	52	greater than, equal to, or less than 0, according as
	53	.I s1
	54	is lexicographically greater than, equal to, or less than
	55	.IR s2 .
	56	.I Strncmp
	57	makes the same comparison but looks at at most
	58	.I n
	59	characters.
	60	.PP
	61	.I Strcpy
	62	copies string
	63	.I s2
	64	to
65	.I s1,
66	stopping after the null character has been moved.
67	.I Strncpy
68	copies exactly
69	.I n
70	characters, truncating or null-padding
71	.I s2;
72	the target may not be null-terminated if the length of
73	.I s2
74	is
75	.I n
76	or more. Both return
77	.IR s1 .
78	.PP
79	.I Strlen
80	returns the number of non-null characters in
81	.IR s .
82	.PP
83	.I Index
84	.RI ( rindex )
85	returns a pointer to the first (last) occurrence of character
86	.I c
87	in string
88	.I s,
89	or zero if
90	.I c
91	does not occur in the string.