50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
/*
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* Library routine to GET the Current Working Directory.
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* arg1 is a pointer to a character buffer into which the
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* path name of the current directory is placed by the
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* subroutine. arg1 may be zero, in which case the
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* subroutine will call malloc to get the required space.
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* arg2 is the length of the buffer space for the path-name.
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* If the actual path-name is longer than (arg2-2), or if
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* the value of arg2 is not at least 3, the subroutine will
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* return a value of zero, with errno set as appropriate.
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*/
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#include <stdio.h>
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#include <errno.h>
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extern FILE *popen();
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extern char *malloc(), *fgets(), *strchr();
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extern int errno, pclose();
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char *
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getcwd(arg1, arg2)
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char *arg1;
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int arg2;
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{
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FILE *pipe;
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char *trm;
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if(arg2 == 0) {
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errno = EINVAL;
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return(0);
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}
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if(arg1 == 0)
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if((arg1 = malloc((unsigned)arg2)) == 0) {
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errno = ENOMEM;
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return(0);
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}
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errno = 0;
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if((pipe = popen("pwd", "r")) == 0)
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return(0);
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(void) fgets(arg1, arg2, pipe);
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(void) pclose(pipe);
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trm = strchr(arg1, '\0');
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if(*(trm-1) != '\n') {
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errno = ERANGE;
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return(0);
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}
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*(trm-1) = '\0';
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return(arg1);
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}
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